Add nur

nixos/common.nix

@@ -2,6 +2,7 @@
 
 let
   unstableTarball = fetchTarball https://github.com/NixOS/nixpkgs/archive/nixpkgs-unstable.tar.gz;
+  nurTarball = fetchTarball https://github.com/nix-community/NUR/archive/master.tar.gz;
 in
   {
     imports =
@@ -22,6 +23,9 @@ in
           unstable = import unstableTarball {
             config = config.nixpkgs.config;
           };
+          nur = import nurTarball {
+            inherit pkgs;
+          };
         };
       };