modules: networking: add 'wireless' option

modules/networking.nix

@@ -1,7 +1,10 @@
-{ lib, ... }:
-
+{ config, lib, ... }:
+let
+  cfg = config.my.networking;
+in
 {
-  options.my.networking.externalInterface = with lib; mkOption {
+  options.my.networking = with lib; {
+    externalInterface = mkOption {
       type = types.nullOr types.str;
       default = null;
       example = "eth0";
@@ -10,4 +13,15 @@
         e.g. NATing internal networks.
       '';
     };
+
+    wireless = {
+      enable = mkEnableOption "wireless configuration";
+    };
+  };
+
+  config = lib.mkMerge [
+    (lib.mkIf cfg.wireless.enable {
+      networking.networkmanager.enable = true;
+    })
+  ];
 }