Fix the BipedalWalkerHardCore environment name

README.md

@@ -87,5 +87,5 @@ Once an experiment is finished, you can see inspect results like in `tutorial.ip
 | InvPendSwingUp        | InvertedPendulumSwingupBulletEnv-v0 |
 | LunarLander           | LunarLanderContinuous-v2            |
 | BipedalWalker         | BipedalWalker-v3                    |
-| BipedalWalkerHardCore |                                     |
+| BipedalWalkerHardCore | BipedalWalkerHardcore-v2            |
 | Hopper                | HopperBulletEnv-v0                  |