Move NixOS module out of flake-utils

flake.nix

@@ -6,7 +6,8 @@
   };
 
   outputs = { self, nixpkgs, flake-utils, rust-overlay, ... }:
-    flake-utils.lib.eachDefaultSystem (system:
+  {
+    packages = flake-utils.lib.eachDefaultSystem (system:
       let
         overlays = [ (import rust-overlay) ];
         pkgs = import nixpkgs { inherit system overlays; };
@@ -27,10 +28,12 @@
           buildInputs =
             [ (rustVersion.override { extensions = [ "rust-src" ]; }) ];
         };
-        nixosModules.default = { config, lib, pkgs, ... }:
-          with lib;
-          let cfg = config.mawalu.services.norbert;
-          in
+      }
+    );
+    nixosModules.default = { config, lib, pkgs, ... }:
+      with lib;
+      let cfg = config.mawalu.services.norbert;
+      in
         {
           options.mawalu.services.rail = {
             enable = mkEnableOption "Enable the rail tmpmail server";
@@ -50,7 +53,5 @@
             };
           };
         };
-
-      }
-    );
+  };
 }