Update README.md & steam

modules/nixos/gui/games/default.nix

@@ -0,0 +1,14 @@
+{ lib, config, pkgs, ... }:
+let cfg = config.hostcfg.make.game;
+in {
+  config = lib.mkIf cfg {
+
+    programs.steam = {
+      enable = true;
+      remotePlay.openFirewall =
+        true; # Open ports in the firewall for Steam Remote Play
+      dedicatedServer.openFirewall =
+        true; # Open ports in the firewall for Source Dedicated Server
+    };
+  };
+}