add vmvariant as preset

platforms/nixos/modules/nmasur/presets/vm.nix

@@ -0,0 +1,31 @@
+{
+  config,
+  lib,
+  ...
+}:
+
+let
+  cfg = config.nmasur.presets.vm;
+in
+
+{
+
+  options.nmasur.presets.vm.enable = lib.mkEnableOption "VM-specific settings for testing";
+
+  config = lib.mkIf cfg.enable {
+
+    # Settings for testing in a VM
+    virtualisation.vmVariant = {
+      home-manager.users."noah".programs.nix-index.enable = false;
+      nmasur.presets.services.openssh.enable = true;
+      virtualisation.forwardPorts = [
+        {
+          from = "host";
+          host.port = 2222;
+          guest.port = 22;
+        }
+      ];
+    };
+
+  };
+}