Migration guide - list removed APIs with replacements (#5307)

* list removed APIs with replacements

* fixes

com.unity.ml-agents/CHANGELOG.md

 #### com.unity.ml-agents / com.unity.ml-agents.extensions (C#)
 - The minimum supported Unity version was updated to 2019.4. (#5166)
 - Several breaking interface changes were made. See the
-[Migration Guide](https://github.com/Unity-Technologies/ml-agents/blob/release_14_docs/docs/Migrating.md) for more
+[Migration Guide](https://github.com/Unity-Technologies/ml-agents/blob/release_17_docs/docs/Migrating.md) for more
 details.
 - Some methods previously marked as `Obsolete` have been removed. If you were using these methods, you need to replace them with their supported counterpart.
 - The interface for disabling discrete actions in `IDiscreteActionMask` has changed.

docs/Migrating.md

 # Upgrading
 
-## :warning: Warning :warning:
-
-The C# editor code and python trainer code are not compatible between releases.
-This means that if you upgrade one, you _must_ upgrade the other as well. If you
-experience new errors or unable to connect to training after updating, please
-double-check that the versions are in the same. The versions can be found in
-
-- `Academy.k_ApiVersion` in Academy.cs
-  ([example](https://github.com/Unity-Technologies/ml-agents/blob/b255661084cb8f701c716b040693069a3fb9a257/UnitySDK/Assets/ML-Agents/Scripts/Academy.cs#L95))
-- `UnityEnvironment.API_VERSION` in environment.py
-  ([example](https://github.com/Unity-Technologies/ml-agents/blob/b255661084cb8f701c716b040693069a3fb9a257/ml-agents-envs/mlagents/envs/environment.py#L45))
-
-
 # Migrating
 ## Migrating the package to version 2.0
 - The official version of Unity ML-Agents supports is now 2019.4 LTS. If you run
 deprecated APIs have been removed. See the migration steps bellow for specific API replacements.
+
+### Deprecated methods removed
+| **Deprecated API** | **Suggested Replacement** |
+|:-------:|:------:|
+| `IActuator ActuatorComponent.CreateActuator()` | `IActuator[] ActuatorComponent.CreateActuators()` |
+| `IActionReceiver.PackActions(in float[] destination)` | none |
+| `Agent.CollectDiscreteActionMasks(DiscreteActionMasker actionMasker)` | `Agent.WriteDiscreteActionMask(IDiscreteActionMask actionMask)` |
+| `Agent.Heuristic(float[] actionsOut)` | `Agent.Heuristic(in ActionBuffers actionsOut)` |
+| `Agent.OnActionReceived(float[] vectorAction)` | `Agent.OnActionReceived(ActionBuffers actions)` |
+| `Agent.GetAction()` | `Agent.GetStoredActionBuffers()` |
+| `BrainParameters.SpaceType`, `VectorActionSize`, `VectorActionSpaceType`, and `NumActions` | `BrainParameters.ActionSpec` |
+| `ObservationWriter.AddRange(IEnumerable<float> data, int writeOffset = 0)` | `ObservationWriter. AddList(IList<float> data, int writeOffset = 0` |
+| `SensorComponent.IsVisual()` and `IsVector()` | none |
+| `VectorSensor.AddObservation(IEnumerable<float> observation)` | `VectorSensor.AddObservation(IList<float> observation)` |
+| `SideChannelsManager` | `SideChannelManager` |
+
 ### IDiscreteActionMask changes
 - The interface for disabling specific discrete actions has changed. `IDiscreteActionMask.WriteMask()` was removed,
 and replaced with `SetActionEnabled()`. Instead of returning an IEnumerable with indices to disable, you can