pinwheel: Add scala module

hosts/pinwheel/modules/scala/default.nix

@@ -0,0 +1,19 @@
+{ pkgs, lib, config, ... }:
+let
+  enabled = config.mod.scala.enable;
+in
+{
+  options = {
+    mod.scala = {
+      enable = lib.mkEnableOption "enable scala module";
+    };
+  };
+
+  config = lib.mkIf enabled {
+    home-manager.users.alex = {
+      home.packages = [
+        pkgs.metals
+      ];
+    };
+  };
+}