Clarify instructions on getting a dev engine capable room (#3007)

Author: sprunk

ZkLobbyServer/autohost/Commands/CmdEngine.cs

@@ -23,7 +23,7 @@ public override string Arm(ServerBattle battle, Say e, string arguments = null)
 
             if ((battle.Mode != AutohostMode.None || !battle.IsPassworded) && engine != battle.server.Engine && !battle.IsAutohost)
             {
-                battle.Respond(e, $"You cannot change engine to version other than {battle.server.Engine} here, use custom passworded room");
+                battle.Respond(e, $"You cannot change engine to version other than {battle.server.Engine} here, must be the Custom room type (say '!type custom') and passworded (say '!password bla', can remove it afterwards via '!password')");
                 return null;
             }