Add note on RayPerception change (#2837)

* Add note on RayPerception change

* Update Migrating.md

docs/Migrating.md

 # Migrating
 
-## Migrating from ML-Agents toolkit v0.10 to v0.11
+## Migrating from ML-Agents toolkit v0.11.0
+
+### Important Changes
+
+### Steps to Migrate
+* We [fixed a bug](https://github.com/Unity-Technologies/ml-agents/pull/2823) in `RayPerception3d.Perceive()` that was causing the `endOffset` to be used incorrectly. However this may produce different behavior from previous versions if you use a non-zero `startOffset`. To reproduce the old behavior, you should increase the the value of `endOffset` by `startOffset`. You can verify your raycasts are performing as expected in scene view using the debug rays.
+
+## Migrating from ML-Agents toolkit v0.10 to v0.11.0
 
 ### Important Changes
 * The definition of the gRPC service has changed.