nginx: Make VM testing easier by binding virtualHosts to localhost

modules/default.nix

@@ -1,5 +1,12 @@
-{ ... }:
+{ lib, ... }:
+
+with lib;
 
 {
   imports = [ ./virtualisation/pods.nix ];
+
+  options.services.nginx.domain = mkOption {
+    type = types.str;
+    description = "The base domain name to append to virtual domain names";
+  };
 }