added plasma

system/wm/plasma.nix

@@ -0,0 +1,11 @@
+{ config, lib, pkgs, ... }:
+{
+  imports = [
+    ./dbus.nix
+  ];
+  services.displayManager.plasma6.enable = true;
+
+  environment.plasma6.excludePackages = with pkgs.kdePackages; [
+    plasma-browser-integration
+  ];
+}