Add PPO Tutorial (#2156)

Author: vmoens

_static/img/invpendulum.gif

@@ -76,6 +76,8 @@
 
 intersphinx_mapping = {
     "torch": ("https://pytorch.org/docs/stable/", None),
+    "tensordict": ("https://pytorch-labs.github.io/tensordict/", None),
+    "torchrl": ("https://pytorch.org/rl/", None),
     "torchaudio": ("https://pytorch.org/audio/stable/", None),
     "torchtext": ("https://pytorch.org/text/stable/", None),
     "torchvision": ("https://pytorch.org/vision/stable/", None),

conf.py

@@ -269,6 +269,13 @@ What's new in PyTorch tutorials?
    :link: intermediate/reinforcement_q_learning.html
    :tags: Reinforcement-Learning
 
+.. customcarditem::
+   :header: Reinforcement Learning (PPO) with TorchRL
+   :card_description: Learn how to use PyTorch and TorchRL to train a Proximal Policy Optimization agent on the Inverted Pendulum task from Gym.
+   :image: _static/img/invpendulum.gif
+   :link: intermediate/reinforcement_ppo.html
+   :tags: Reinforcement-Learning
+
 .. customcarditem::
    :header: Train a Mario-playing RL Agent
    :card_description: Use PyTorch to train a Double Q-learning agent to play Mario.
@@ -874,6 +881,7 @@ Additional Resources
    :caption: Reinforcement Learning
 
    intermediate/reinforcement_q_learning
+   intermediate/reinforcement_ppo
    intermediate/mario_rl_tutorial
 
 .. toctree::