add citizen theme to mediawiki

flake.nix

@@ -21,6 +21,11 @@
       #FIXME: Podrá volver a "nixpkgs" una vez que rocksdb.enableLiburing llegue a stable
       inputs.nixpkgs.follows = "unstable";
     };
+
+    mediawikiSkinCitizen = {
+      url = "github:StarCitizenTools/mediawiki-skins-Citizen/v2.27.0";
+      flake = false;
+    };
   };
 
   outputs =
@@ -33,6 +38,7 @@
     , vpsadminos
     , homepage
     , conduwuit
+    , mediawikiSkinCitizen
     }:
     let
       system = "x86_64-linux";