pinwheel: Add direnv module

hosts/pinwheel/modules/direnv/default.nix

@@ -0,0 +1,15 @@
+{ lib, config, ... }:
+let
+  zshEnabled = config.mod.zsh.enable;
+in
+{
+  home-manager.users.alex = {
+    programs.direnv = {
+      enable = true;
+      nix-direnv.enable = true;
+    };
+
+
+    programs.direnv.enableZshIntegration = lib.mkIf zshEnabled true;
+  };
+}