doc: make sure section depths are consecutive

skipping heading levels (eg from # to ###, or starting at ###) is legal
in pandoc, but not in nixos-render-docs. pandoc acts as though section
levels *were* consecutive, nixos-render-docs prefers to tell people not
to do that kind of thing because it can make documents more fragile.

doc/builders/special/makesetuphook.section.md

@@ -12,7 +12,7 @@ pkgs.makeSetupHook {
 } ./script.sh
 ```
 
-#### setup hook that depends on the hello package and runs hello and @shell@ is substituted with path to bash {#sec-pkgs.makeSetupHook-usage-example}
+### setup hook that depends on the hello package and runs hello and @shell@ is substituted with path to bash {#sec-pkgs.makeSetupHook-usage-example}
 
 ```nix
 pkgs.makeSetupHook {

doc/hooks/autoconf.section.md

@@ -1,4 +1,3 @@
-
-### Autoconf {#setup-hook-autoconf}
+# Autoconf {#setup-hook-autoconf}
 
 The `autoreconfHook` derivation adds `autoreconfPhase`, which runs autoreconf, libtoolize and automake, essentially preparing the configure script in autotools-based builds. Most autotools-based packages come with the configure script pre-generated, but this hook is necessary for a few packages and when you need to patch the package’s configure scripts.

doc/hooks/automake.section.md

@@ -1,4 +1,3 @@
-
-### Automake {#setup-hook-automake}
+# Automake {#setup-hook-automake}
 
 Adds the `share/aclocal` subdirectory of each build input to the `ACLOCAL_PATH` environment variable.

doc/hooks/autopatchelf.section.md

@@ -1,5 +1,4 @@
-
-### autoPatchelfHook {#setup-hook-autopatchelfhook}
+# autoPatchelfHook {#setup-hook-autopatchelfhook}
 
 This is a special setup hook which helps in packaging proprietary software in that it automatically tries to find missing shared library dependencies of ELF files based on the given `buildInputs` and `nativeBuildInputs`.
 

doc/hooks/breakpoint.section.md

@@ -1,5 +1,4 @@
-
-### breakpointHook {#breakpointhook}
+# breakpointHook {#breakpointhook}
 
 This hook will make a build pause instead of stopping when a failure happens. It prevents nix from cleaning up the build environment immediately and allows the user to attach to a build environment using the `cntr` command. Upon build error it will print instructions on how to use `cntr`, which can be used to enter the environment for debugging. Installing cntr and running the command will provide shell access to the build sandbox of failed build. At `/var/lib/cntr` the sandboxed filesystem is mounted. All commands and files of the system are still accessible within the shell. To execute commands from the sandbox use the cntr exec subcommand. `cntr` is only supported on Linux-based platforms. To use it first add `cntr` to your `environment.systemPackages` on NixOS or alternatively to the root user on non-NixOS systems. Then in the package that is supposed to be inspected, add `breakpointHook` to `nativeBuildInputs`.
 

doc/hooks/cmake.section.md

@@ -1,4 +1,3 @@
-
-### cmake {#cmake}
+# cmake {#cmake}
 
 Overrides the default configure phase to run the CMake command. By default, we use the Make generator of CMake. In addition, dependencies are added automatically to `CMAKE_PREFIX_PATH` so that packages are correctly detected by CMake. Some additional flags are passed in to give similar behavior to configure-based packages. You can disable this hook’s behavior by setting `configurePhase` to a custom value, or by setting `dontUseCmakeConfigure`. `cmakeFlags` controls flags passed only to CMake. By default, parallel building is enabled as CMake supports parallel building almost everywhere. When Ninja is also in use, CMake will detect that and use the ninja generator.

doc/hooks/gdk-pixbuf.section.md

@@ -1,4 +1,3 @@
-
-### gdk-pixbuf {#setup-hook-gdk-pixbuf}
+# gdk-pixbuf {#setup-hook-gdk-pixbuf}
 
 Exports `GDK_PIXBUF_MODULE_FILE` environment variable to the builder. Add librsvg package to `buildInputs` to get svg support. See also the [setup hook description in GNOME platform docs](#ssec-gnome-hooks-gdk-pixbuf).

doc/hooks/ghc.section.md

@@ -1,4 +1,3 @@
-
-### GHC {#ghc}
+# GHC {#ghc}
 
 Creates a temporary package database and registers every Haskell build input in it (TODO: how?).

doc/hooks/gnome.section.md

@@ -1,4 +1,3 @@
-
-### GNOME platform {#gnome-platform}
+# GNOME platform {#gnome-platform}
 
 Hooks related to GNOME platform and related libraries like GLib, GTK and GStreamer are described in [](#sec-language-gnome).

doc/hooks/installShellFiles.section.md

@@ -1,5 +1,4 @@
-
-### `installShellFiles` {#installshellfiles}
+# `installShellFiles` {#installshellfiles}
 
 This hook helps with installing manpages and shell completion files. It exposes 2 shell functions `installManPage` and `installShellCompletion` that can be used from your `postInstall` hook.
 

doc/hooks/libiconv.section.md

@@ -1,4 +1,3 @@
-
-### libiconv, libintl {#libiconv-libintl}
+# libiconv, libintl {#libiconv-libintl}
 
 A few libraries automatically add to `NIX_LDFLAGS` their library, making their symbols automatically available to the linker. This includes libiconv and libintl (gettext). This is done to provide compatibility between GNU Linux, where libiconv and libintl are bundled in, and other systems where that might not be the case. Sometimes, this behavior is not desired. To disable this behavior, set `dontAddExtraLibs`.

doc/hooks/libxml2.section.md

@@ -1,4 +1,3 @@
-
-### libxml2 {#setup-hook-libxml2}
+# libxml2 {#setup-hook-libxml2}
 
 Adds every file named `catalog.xml` found under the `xml/dtd` and `xml/xsl` subdirectories of each build input to the `XML_CATALOG_FILES` environment variable.

doc/hooks/meson.section.md

@@ -1,26 +1,25 @@
-
-### Meson {#meson}
+# Meson {#meson}
 
 Overrides the configure phase to run meson to generate Ninja files. To run these files, you should accompany Meson with ninja. By default, `enableParallelBuilding` is enabled as Meson supports parallel building almost everywhere.
 
-#### Variables controlling Meson {#variables-controlling-meson}
+## Variables controlling Meson {#variables-controlling-meson}
 
-##### `mesonFlags` {#mesonflags}
+### `mesonFlags` {#mesonflags}
 
 Controls the flags passed to meson.
 
-##### `mesonBuildType` {#mesonbuildtype}
+### `mesonBuildType` {#mesonbuildtype}
 
 Which [`--buildtype`](https://mesonbuild.com/Builtin-options.html#core-options) to pass to Meson. We default to `plain`.
 
-##### `mesonAutoFeatures` {#mesonautofeatures}
+### `mesonAutoFeatures` {#mesonautofeatures}
 
 What value to set [`-Dauto_features=`](https://mesonbuild.com/Builtin-options.html#core-options) to. We default to `enabled`.
 
-##### `mesonWrapMode` {#mesonwrapmode}
+### `mesonWrapMode` {#mesonwrapmode}
 
 What value to set [`-Dwrap_mode=`](https://mesonbuild.com/Builtin-options.html#core-options) to. We default to `nodownload` as we disallow network access.
 
-##### `dontUseMesonConfigure` {#dontusemesonconfigure}
+### `dontUseMesonConfigure` {#dontusemesonconfigure}
 
 Disables using Meson’s `configurePhase`.

doc/hooks/ninja.section.md

@@ -1,4 +1,3 @@
-
-### ninja {#ninja}
+# ninja {#ninja}
 
 Overrides the build, install, and check phase to run ninja instead of make. You can disable this behavior with the `dontUseNinjaBuild`, `dontUseNinjaInstall`, and `dontUseNinjaCheck`, respectively. Parallel building is enabled by default in Ninja.

doc/hooks/perl.section.md

@@ -1,4 +1,3 @@
-
-### Perl {#setup-hook-perl}
+# Perl {#setup-hook-perl}
 
 Adds the `lib/site_perl` subdirectory of each build input to the `PERL5LIB` environment variable. For instance, if `buildInputs` contains Perl, then the `lib/site_perl` subdirectory of each input is added to the `PERL5LIB` environment variable.

doc/hooks/pkg-config.section.md

@@ -1,4 +1,3 @@
-
-### pkg-config {#setup-hook-pkg-config}
+# pkg-config {#setup-hook-pkg-config}
 
 Adds the `lib/pkgconfig` and `share/pkgconfig` subdirectories of each build input to the `PKG_CONFIG_PATH` environment variable.

doc/hooks/python.section.md

@@ -1,4 +1,3 @@
-
-### Python {#setup-hook-python}
+# Python {#setup-hook-python}
 
 Adds the `lib/${python.libPrefix}/site-packages` subdirectory of each build input to the `PYTHONPATH` environment variable.

doc/hooks/qt-4.section.md

@@ -1,4 +1,3 @@
-
-### Qt 4 {#qt-4}
+# Qt 4 {#qt-4}
 
 Sets the `QTDIR` environment variable to Qt’s path.

doc/hooks/scons.section.md

@@ -1,4 +1,3 @@
-
-### scons {#scons}
+# scons {#scons}
 
 Overrides the build, install, and check phases. This uses the scons build system as a replacement for make. scons does not provide a configure phase, so everything is managed at build and install time.

doc/hooks/tetex-tex-live.section.md

@@ -1,4 +1,3 @@
-
-### teTeX / TeX Live {#tetex-tex-live}
+# teTeX / TeX Live {#tetex-tex-live}
 
 Adds the `share/texmf-nix` subdirectory of each build input to the `TEXINPUTS` environment variable.

doc/hooks/unzip.section.md

@@ -1,4 +1,3 @@
-
-### unzip {#unzip}
+# unzip {#unzip}
 
 This setup hook will allow you to unzip .zip files specified in `$src`. There are many similar packages like `unrar`, `undmg`, etc.

doc/hooks/validatePkgConfig.section.md

@@ -1,4 +1,3 @@
-
-### validatePkgConfig {#validatepkgconfig}
+# validatePkgConfig {#validatepkgconfig}
 
 The `validatePkgConfig` hook validates all pkg-config (`.pc`) files in a package. This helps catching some common errors in pkg-config files, such as undefined variables.

doc/hooks/waf.section.md

@@ -1,4 +1,3 @@
-
-### wafHook {#wafhook}
+# wafHook {#wafhook}
 
 Overrides the configure, build, and install phases. This will run the “waf” script used by many projects. If `wafPath` (default `./waf`) doesn’t exist, it will copy the version of waf available in Nixpkgs. `wafFlags` can be used to pass flags to the waf script.

doc/hooks/xcbuild.section.md

@@ -1,4 +1,3 @@
-
-### xcbuildHook {#xcbuildhook}
+# xcbuildHook {#xcbuildhook}
 
 Overrides the build and install phases to run the "xcbuild" command. This hook is needed when a project only comes with build files for the XCode build system. You can disable this behavior by setting buildPhase and configurePhase to a custom value. xcbuildFlags controls flags passed only to xcbuild.

doc/languages-frameworks/gnome.section.md

@@ -137,15 +137,15 @@ Most GNOME package offer [`updateScript`](#var-passthru-updateScript), it is the
 
 ## Frequently encountered issues {#ssec-gnome-common-issues}
 
-#### `GLib-GIO-ERROR **: 06:04:50.903: No GSettings schemas are installed on the system` {#ssec-gnome-common-issues-no-schemas}
+### `GLib-GIO-ERROR **: 06:04:50.903: No GSettings schemas are installed on the system` {#ssec-gnome-common-issues-no-schemas}
 
 There are no schemas available in `XDG_DATA_DIRS`. Temporarily add a random package containing schemas like `gsettings-desktop-schemas` to `buildInputs`. [`glib`](#ssec-gnome-hooks-glib) and [`wrapGAppsHook`](#ssec-gnome-hooks-wrapgappshook) setup hooks will take care of making the schemas available to application and you will see the actual missing schemas with the [next error](#ssec-gnome-common-issues-missing-schema). Or you can try looking through the source code for the actual schemas used.
 
-#### `GLib-GIO-ERROR **: 06:04:50.903: Settings schema ‘org.gnome.foo’ is not installed` {#ssec-gnome-common-issues-missing-schema}
+### `GLib-GIO-ERROR **: 06:04:50.903: Settings schema ‘org.gnome.foo’ is not installed` {#ssec-gnome-common-issues-missing-schema}
 
 Package is missing some GSettings schemas. You can find out the package containing the schema with `nix-locate org.gnome.foo.gschema.xml` and let the hooks handle the wrapping as [above](#ssec-gnome-common-issues-no-schemas).
 
-#### When using `wrapGAppsHook` with special derivers you can end up with double wrapped binaries. {#ssec-gnome-common-issues-double-wrapped}
+### When using `wrapGAppsHook` with special derivers you can end up with double wrapped binaries. {#ssec-gnome-common-issues-double-wrapped}
 
 This is because derivers like `python.pkgs.buildPythonApplication` or `qt5.mkDerivation` have setup-hooks automatically added that produce wrappers with makeWrapper. The simplest way to workaround that is to disable the `wrapGAppsHook` automatic wrapping with `dontWrapGApps = true;` and pass the arguments it intended to pass to makeWrapper to another.
 
@@ -193,7 +193,7 @@ mkDerivation {
 }
 ```
 
-#### I am packaging a project that cannot be wrapped, like a library or GNOME Shell extension. {#ssec-gnome-common-issues-unwrappable-package}
+### I am packaging a project that cannot be wrapped, like a library or GNOME Shell extension. {#ssec-gnome-common-issues-unwrappable-package}
 
 You can rely on applications depending on the library setting the necessary environment variables but that is often easy to miss. Instead we recommend to patch the paths in the source code whenever possible. Here are some examples:
 
@@ -209,6 +209,6 @@ You can rely on applications depending on the library setting the necessary envi
 
   []{#ssec-gnome-common-issues-unwrappable-package-gsettings-c} [Hard-coding GSettings schema path in C library](https://github.com/NixOS/nixpkgs/blob/29c120c065d03b000224872251bed93932d42412/pkgs/development/libraries/glib-networking/default.nix#L31-L34) – nothing special other than using [Coccinelle patch](https://github.com/NixOS/nixpkgs/pull/67957#issuecomment-527717467) to generate the patch itself.
 
-#### I need to wrap a binary outside `bin` and `libexec` directories. {#ssec-gnome-common-issues-weird-location}
+### I need to wrap a binary outside `bin` and `libexec` directories. {#ssec-gnome-common-issues-weird-location}
 
 You can manually trigger the wrapping with `wrapGApp` in `preFixup` phase. It takes a path to a program as a first argument; the remaining arguments are passed directly to [`wrapProgram`](#fun-wrapProgram) function.