Extract a dwm profile module

I've made this a module as it imports configuration from `st` and
potentially others as I continue to refactor.

modules/nixos/desktop/default.nix

@@ -1,6 +1,5 @@
 {
   imports = [
-    ./dwm.nix
     ./screenkey.nix
   ];
 }

modules/nixos/desktop/dwm.nix

@@ -1,43 +0,0 @@
-{
-  config,
-  lib,
-  pkgs,
-  self,
-  ...
-}:
-
-with lib;
-
-{
-  options.nixosModules.dwm.enable = mkEnableOption "Enable dwm";
-
-  config = mkIf config.nixosModules.dwm.enable {
-    services = {
-      dwm-status = {
-        enable = true;
-
-        order = [
-          "audio"
-          "battery"
-          "network"
-          "time"
-        ];
-      };
-
-      xserver = {
-        displayManager.startx.enable = true;
-        windowManager.dwm.enable = true;
-      };
-    };
-
-    systemd.user.services.dwm-status.serviceConfig.Restart = "on-failure";
-
-    environment.systemPackages = with pkgs; [
-      dmenu
-      dmenu-bluetooth
-      networkmanager_dmenu
-      slock
-      xdotool
-    ];
-  };
-}