feat(doc): Add Nix installation option

Signed-off-by: Steffen Vogel <[email protected]>

Author: stv0g

README.md

@@ -111,6 +111,17 @@ Please adjust the environment variables in it and then run:
 docker compose up -d
 ```
 
+#### Nix
+
+GoSƐ is available in [Nixpkgs](https://github.com/NixOS/nixpgks) as well as a flake:
+
+```bash
+nix profile install nixpkgs#gose
+
+# Or via our flake
+nix profile install github:stv0g/gose#gose
+```
+
 ## Configuration
 
 GoSƐ can be configured via a configuration file and/or environment variables

flake.nix

@@ -35,7 +35,10 @@
           ];
         };
 
-        packages.default = pkgs.callPackage ./default.nix { };
+        packages = rec {
+          gose = pkgs.callPackage ./default.nix { };
+          default = gose;
+        };
 
         formatter = pkgs.nixfmt-rfc-style;
       }