[Documentation] Correct MaskedEnv Example in ActionMask Transform Doc…

…umentation (#2060)

torchrl/envs/transforms/transforms.py

@@ -6676,7 +6676,7 @@ class ActionMask(Transform):
         ...         self.observation_spec = CompositeSpec(obs=UnboundedContinuousTensorSpec(3))
         ...         self.reward_spec = UnboundedContinuousTensorSpec(1)
         ...
-        ...     def _reset(self, data):
+        ...     def _reset(self, tensordict=None):
         ...         td = self.observation_spec.rand()
         ...         td.update(torch.ones_like(self.state_spec.rand()))
         ...         return td