[RLlib; Documentation] Added atari pip installs to Pong-v0 example. (#20225)
[RLlib; Documentation] Added atari pip installs to Pong-v0 example. (#20225)

* Added imports to Pongv0 example

* Added comment

* Apply suggestions from code review

Co-authored-by: will <37d41699bdee4fcb969ca499eb0f8b82c60d59cc@anyscale.com>
Co-authored-by: Sven Mika <dd860110a62b19214c4ee03aec0abffecb4e86b8@anyscale.io>
ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray