move some config to user level module

home/david/modules/wallpaper.nix

@@ -0,0 +1,23 @@
+{
+  rootPath,
+  lib,
+  config,
+  ...
+}:
+let
+  cfg = config.david.wallpaper;
+in
+{
+  options = {
+    david.wallpaper = {
+      enable = lib.mkEnableOption "wallpaper";
+    };
+  };
+  config = lib.mkIf cfg.enable {
+    home.file."wallpaper" = {
+      force = true;
+      recursive = true;
+      source = rootPath + "/assets/wallpaper";
+    };
+  };
+}