Merge pull request #258 from CamoCatX/master

Added Nix/NixOS installation to README.md.

Author: mzur

README.md

@@ -53,6 +53,17 @@ On Arch Linux, use [this AUR](https://aur.archlinux.org/packages/gnome-shell-ext
    makepkg -sri
    ```
 
+### Nix/NixOS Method
+
+This extension is already on [Nix packages](https://search.nixos.org/packages?channel=23.05&show=gnomeExtensions.workspace-matrix&from=0&size=50&buckets=%7B%22package_attr_set%22%3A%5B%22gnomeExtensions%22%5D%2C%22package_license_set%22%3A%5B%5D%2C%22package_maintainers_set%22%3A%5B%5D%2C%22package_platforms%22%3A%5B%5D%7D&sort=relevance&type=packages&query=matrix), so it should be as simple as installing it with:
+```
+nix-env -iA nixos.gnomeExtensions.workspace-matrix
+```
+or this for nix (not NixOS) users:
+```
+nix-env -iA nixpkgs.gnomeExtensions.workspace-matrix
+```
+
 ## Known Issues / FAQ
 
 ### How do I restart GNOME Shell?