Update README.md

README.md

@@ -87,6 +87,8 @@ mean_reward, std_reward = evaluate_policy(model, eval_env, n_eval_episodes=10, d
 print(f"mean_reward={mean_reward:.2f} +/- {std_reward}")
 
 # create a video (for colab)
+
+import gymnasium
 from stable_baselines3 import PPO
 from IPython.display import Video, display
 import os