adding protontricks

common/optional/steam.nix

@@ -10,6 +10,7 @@
       gamescopeSession.enable = true;
       remotePlay.openFirewall = true;
       localNetworkGameTransfers.openFirewall = true;
+      protontricks.enable = true;
       extraCompatPackages = with pkgs; [proton-ge-bin];
       extest.enable = true;
     };