added three seconds delay before terminating game when player steps down

ttrs.py

@@ -352,8 +352,10 @@ class TtrsGame(threading.Thread):
 
             evt = self.player.get_event()
             if evt == PlayerEvent.QUIT:
-                self.running = False
-                break
+                time.sleep(3)
+                if self.player.get_event() == PlayerEvent.QUIT:
+                    self.running = False
+                    break
 
             if not self.playground.block_points.isdisjoint(top_row):
                 self.running = False