replace nixfmt with nixpkgs-fmt

nixpkgs-fmt looks like it is going to be the standard formatter for
nixpkgs, so we should follow suite.

CONTRIBUTING.md

@@ -6,11 +6,11 @@ the `template` branch to provide a host of useful NixOS configurations available
 "out of the box". If you wish to contribute such an expression please follow
 these guidelines:
 
-* format your code with [`nixfmt`][nixfmt]
+* format your code with [`nixpkgs-fmt`][nixpkgs-fmt]
 * The commit message follows the same semantics as [nixpkgs][nixpkgs].
   * You can use a `#` symbol to specify ambiguities. For example,
   `develop#zsh: <rest of commit message>` would tell me that your updating the
   `zsh` subprofile living under the `develop` profile.
 
-[nixfmt]: https://github.com/serokell/nixfmt
+[nixpkgs-fmt]: https://github.com/nix-community/nixpkgs-fmt
 [nixpkgs]: https://github.com/NixOS/nixpkgs

profiles/develop/kakoune/default.nix

@@ -6,7 +6,7 @@
     kak-lsp
     kakoune-config
     kakoune-unwrapped
-    nixfmt
+    nixpkgs-fmt
     python3Packages.python-language-server
     rustup
     nix-linter

profiles/develop/kakoune/lint/nix.kak

@@ -4,7 +4,7 @@ hook -group lint global WinSetOption filetype=nix %{
 
   set buffer lintcmd '/etc/xdg/kak/autoload/lint/nix.sh $1'
   lint-enable
-  set buffer formatcmd "nixfmt"
+  set buffer formatcmd "nixpkgs-fmt"
   hook buffer BufWritePre .* %{
     format
     lint

profiles/develop/kakoune/lint/nix.sh

@@ -1,6 +1,6 @@
 #!/usr/bin/env zsh
 
-nix-linter $1 2>&1 | < /dev/stdin > /tmp/lint.out
+nix-linter -W all $1 2>&1 | < /dev/stdin > /tmp/lint.out
 if head -1 /tmp/lint.out | grep Failure &> /dev/null; then
   sed -n 2p /tmp/lint.out | tr '\n' ' '
   printf "error: "