DOC: traini -> train

Author: star1327p

content/tutorial-deep-reinforcement-learning-with-pong-from-pixels.md

@@ -552,7 +552,7 @@ while episode_number < max_episodes:
 
 A few notes:
 
-- If you have previously run an experiment and want to repeat it, your `Monitor` instance may still be running, which may throw an error the next time you try to traini the agent. Therefore, you should first shut down `Monitor` by calling `env.close()` by uncommenting and running the cell below:
+- If you have previously run an experiment and want to repeat it, your `Monitor` instance may still be running, which may throw an error the next time you try to train the agent. Therefore, you should first shut down `Monitor` by calling `env.close()` by uncommenting and running the cell below:
 
 ```python
 # env.close()