Add `agent.pt` and tag the environment

This commit adds a model that is compatible with the 🥇 [Open RL Leaderboard](https://huggingface.co/spaces/open-rl-leaderboard/leaderboard) 🥇.

README.md

@@ -5,6 +5,7 @@ tags:
 - deep-reinforcement-learning
 - reinforcement-learning
 - stable-baselines3
+- Hopper-v4
 model-index:
 - name: TRPO
   results:

agent.pt

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:3107389694ecc21e52f6429dc722bfe7969da5ae8c09dab717b37b2d7918c282
-size 25254
+oid sha256:c112502b082a864b2bd73aa10f59c7d2f26cbd894abbec020e0b0cf40a5d6e35
+size 26378