restructured modules, toggling them, overlays

modules/dev/haskell.nix

@@ -0,0 +1,11 @@
+{ config, pkgs, lib, ... }:
+
+{
+  options = { myHaskell.enable = lib.mkEnableOption "enable"; };
+  config = lib.mkIf config.myHaskell.enable {
+    users.users.jawz.packages = with pkgs; ([
+      ghc # compiler
+      haskell-language-server # lsp
+    ]);
+  };
+}