added go, zig, and ruby, as well as environment

modules/dev/ruby.nix

@@ -0,0 +1,40 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+let
+  packages = builtins.attrValues {
+    inherit (pkgs) ruby; # Ruby interpreter
+    inherit (pkgs.rubyPackages) solargraph; # LSP for Ruby
+  };
+in
+{
+  options = {
+    my.dev.ruby.enable = lib.mkEnableOption "Install Ruby tooling globally";
+    devShells.ruby = lib.mkOption {
+      type = lib.types.package;
+      default = pkgs.mkShell {
+        inherit packages;
+        name = "ruby-dev-shell";
+        shellHook = ''
+          echo "💎 Ruby dev environment"
+        '';
+      };
+      description = "Ruby development shell with interpreter and Solargraph LSP";
+    };
+  };
+  config = lib.mkMerge [
+    (lib.mkIf config.my.dev.ruby.enable {
+      users.users.jawz = { inherit packages; };
+    })
+    {
+      environment.variables = {
+        GEM_HOME = "\${XDG_DATA_HOME}/ruby/gems";
+        GEM_PATH = "\${XDG_DATA_HOME}/ruby/gems";
+        GEM_SPEC_CACHE = "\${XDG_DATA_HOME}/ruby/specs";
+      };
+    }
+  ];
+}