docs(contributing): add a small nix section (#1172)

CONTRIBUTING.md

@@ -12,7 +12,7 @@ all contributors are expected to adhere to.
 
 ## Building
 To build Zellij, we're using cargo-make – you can install it by running `cargo
-install --force cargo-make`. 
+install --force cargo-make`.
 
 To edit our manpage, the mandown crate (`cargo install
 mandown`) is used and the work is done on a markdown file in docs/MANPAGE.md.
@@ -45,6 +45,20 @@ version `wasm-opt --version` > 97, for it's command `wasm-opt`.
 
 To run `test`, you will need the package `pkg-config` and a version of `openssl`.
 
+<details>
+<summary>Should you be a nix (linux/macOs) user, you can use the following
+commands in order to get set up: (expand)</summary>
+
+- `nix develop`
+Download and set up dependencies.
+- `nix build`
+Build the binary in the `result` directory. (--release)
+- `nix run`
+Run the binary.
+- `cachix use zellij`
+Will use our binary cache as a substituter.
+</details>
+
 ## Running the end-to-end tests
 Zellij includes some end-to-end tests which test the whole application as a black-box from the outside.
 These tests work by running a docker container which contains the Zellij binary, connecting to it via ssh, sending some commands and comparing the output received against predefined snapshots.
@@ -59,6 +73,7 @@ These tests work by running a docker container which contains the Zellij binary,
 5. `export CARGO_TARGET_X86_64_UNKNOWN_LINUX_MUSL_LINKER=$CC_x86_64_unknown_linux_musl`
 </details>
 
+
 To run these tests locally, you'll need to have either `docker` or `podman` and also `docker-compose` installed.
 Once you do, in the repository root: