Update app.py

- Add refresh button information

app.py

@@ -197,6 +197,8 @@ with block:
     This is the leaderboard of trained agents during the Deep Reinforcement Learning Course. A free course from beginner to expert.
     
     Just choose which environment you trained your agent on and with Ctrl+F find your rank 🏆
+
+    ** If you don't find your model, go to the bottom of the page and click on the refresh button**
     
     We use **lower bound result to sort the models: mean_reward - std_reward.**