[gaming] Use recommended steam setup

Updated to use programs.steam recommended from the NixOS wiki

machines/nix-book/configuration.nix

@@ -15,7 +15,7 @@
     desktop = {
       enable = true;
       wayland = true;
-      gaming.enable = false;
+      gaming.enable = true;
       kde = true;
       sddm = true;
     };

roles/desktop/gaming.nix

@@ -9,7 +9,6 @@ in
   config = mkMerge [
     (mkIf (cfg.enable && cfg.gaming.enable) {
       environment.systemPackages = with pkgs; [
-        steam
         lutris
         moonlight
 
@@ -19,11 +18,18 @@ in
         retroarch-full
         ryubing
       ];
+
+      programs.steam = {
+        enable = true;
+        remotePlay.openFirewall = true;
+        dedicatedServer.openFirewall = true;
+        localNetworkGameTransfers.openFirewall = true;
+      };
+
       # TODO: Remove me once dolphin-emu and dolphin-emu-primehack update
       #       dependencies to mbedtls from mbedtls_2 (which is currently)
       #       unmaintained
       nixpkgs.config.permittedInsecurePackages = [ "mbedtls-2.28.10" ];
-
       warnings = [
         "Using insecure mbedtls-2.28.10 for Dolphin Emu - check for updates regularly"
       ];