snowfall migration

lib/module/default.nix

@@ -0,0 +1,19 @@
+{ lib, ... }:
+let
+  inherit (lib) mkOption types;
+in
+rec {
+  mkOpt =
+    type: default: description:
+    mkOption { inherit type default description; };
+
+  mkBoolOpt = mkOpt types.bool;
+
+  enabled = {
+    enable = true;
+  };
+
+  disabled = {
+    enable = false;
+  };
+}