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:a1f5d28f29f709c3e6b7b9aaebc07ddc83b98674641fa429681d6e5d230ad05b
-size 25254
+oid sha256:29e330af634954e41625d240e7562d0ecdc30508302fbd530c04ebd8fce8f452
+size 26378