Rename nvidia option, move gui stuff to its own file

gui.nix

@@ -0,0 +1,28 @@
+{ ... }: {
+  programs.gnome-disks.enable = true;
+
+  services.xserver = {
+    enable = true;
+    xkb = {
+      variant = "";
+      layout = "us";
+    };
+    videoDrivers = [ "nvidia" ];
+
+    # Enable the KDE Plasma Desktop Environment.
+    desktopManager.plasma5.enable = true;
+  };
+
+  sound.enable = true;
+  hardware.pulseaudio.enable = false;
+  security = {
+    sudo.wheelNeedsPassword = false;
+    rtkit.enable = true;
+  };
+  services.pipewire = {
+    enable = true;
+    alsa.enable = true;
+    alsa.support32Bit = true;
+    pulse.enable = true;
+  };
+}