modularize system config

modules/system/desktop.nix

@@ -0,0 +1,30 @@
+{ pkgs, enable-dm, ... }: {
+  hardware.graphics = {
+    enable = true;
+    extraPackages = [ pkgs.libva-vdpau-driver ];
+  };
+
+  services = {
+    displayManager.gdm.enable = enable-dm;
+    xserver = {
+      enable = true;
+      xkb = {
+        layout = "us";
+        variant = "";
+      };
+    };
+    pipewire = {
+      enable = true;
+      alsa.enable = true;
+      alsa.support32Bit = true;
+      pulse.enable = true;
+      jack.enable = true;
+    };
+    gnome.gnome-keyring.enable = true;
+    gvfs.enable = true;
+    blueman.enable = true;
+    pulseaudio.enable = false;
+  };
+
+  security.rtkit.enable = true;
+}