move unspecific options to boilerplate with let-in in flake.nix

flake.nix

@@ -31,13 +31,9 @@
       nixcord,
       ...
     }@inputs:
-    {
-      nixosConfigurations.nerv = nixpkgs.lib.nixosSystem {
-        specialArgs = { inherit inputs; };
-        modules = [
+    let
+      boilerplate = [
         ./modules/themeing
-
-          ./modules/hosts/nerv/configuration.nix
         home-manager.nixosModules.home-manager
         {
           home-manager.useGlobalPkgs = true;
@@ -50,6 +46,14 @@
           home-manager.users.lucy = ./modules/hosts/base/home.nix;
         }
       ];
+    in
+    {
+      nixosConfigurations.nerv = nixpkgs.lib.nixosSystem {
+        specialArgs = { inherit inputs; };
+        modules = [
+          ./modules/hosts/nerv/configuration.nix
+        ]
+        ++ boilerplate;
       };
 
     };