Modularize dev/zsh.nix

modules/dev/default.nix

@@ -15,7 +15,7 @@
     ./rust.nix
     ./scala.nix
     ./unity3d.nix
-    # ./zsh.nix
+    ./zsh.nix
   ];
 
   options = {};

modules/dev/zsh.nix

@@ -5,10 +5,20 @@
 # mortals to question the will of the ancient ones. If they want shell programs,
 # they get shell programs.
 
-{ pkgs, ... }:
+{ config, options, lib, pkgs, ... }:
+with lib;
 {
+  options.modules.dev.zsh = {
+    enable = mkOption {
+      type = types.bool;
+      default = false;
+    };
+  };
+
+  config = mkIf config.modules.dev.zsh.enable {
     my.packages = with pkgs; [
       shellcheck
       my.zunit
     ];
+  };
 }