adding desktop config

modules/nixos/cups.nix

@@ -0,0 +1,19 @@
+{ pkgs, ... }:
+
+{
+  # Enable CUPS to print documents.
+  services.printing.enable = true;
+
+  services.avahi = {
+    enable = true;
+    nssmdns4 = true;
+    openFirewall = true;
+  };
+
+  # Printing
+  services.printing.drivers = [
+    pkgs.brlaser
+    pkgs.brgenml1lpr
+    pkgs.brgenml1cupswrapper
+  ];
+}