Update colab doc

Author: maryamziaa

com.unity.ml-agents/Documentation~/TableOfContents.md

@@ -16,10 +16,10 @@
   * [Python Gym API](Python-Gym-API.md)
   * [Python PettingZoo API](Python-PettingZoo-API.md)
   * [Python Low-Level API](Python-LLAPI.md)
-* [Python Tutorial with Google Colab]
-  * [Using a UnityEnvironment]
-  * [Q-Learning with a UnityEnvironment]
-  * [Using Side Channels on a UnityEnvironment]
+* [Python Tutorial with Google Colab](Tutorial-Colab.md)
+  * [Using a UnityEnvironment](https://colab.research.google.com/github/Unity-Technologies/ml-agents/blob/release_22_docs/colab/Colab_UnityEnvironment_1_Run.ipynb)
+  * [Q-Learning with a UnityEnvironment](https://colab.research.google.com/github/Unity-Technologies/ml-agents/blob/release_22_docs/colab/Colab_UnityEnvironment_2_Train.ipynb)
+  * [Using Side Channels on a UnityEnvironment](https://colab.research.google.com/github/Unity-Technologies/ml-agents/blob/release_22_docs/colab/Colab_UnityEnvironment_3_SideChannel.ipynb)
 * [Advanced Features](Advanced-Features.md)
   * [Custom Side Channels](Custom-SideChannels.md)
   * [Custom Grid Sensors](Custom-GridSensors.md)

com.unity.ml-agents/Documentation~/Tutorial-Colab.md

@@ -0,0 +1,9 @@
+# Python Tutorial with Google Colab
+
+Interactive tutorials for using ML-Agents with Google Colab environments.
+
+| **Tutorial**                                                                                                                                                                              | **Description**                                                    |
+|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------|
+| [Using a UnityEnvironment](https://colab.research.google.com/github/Unity-Technologies/ml-agents/blob/release_22_docs/colab/Colab_UnityEnvironment_1_Run.ipynb)                           | Learn how to set up and interact with Unity environments in Colab. |
+| [Q-Learning with a UnityEnvironment](https://colab.research.google.com/github/Unity-Technologies/ml-agents/blob/release_22_docs/colab/Colab_UnityEnvironment_2_Train.ipynb)               | Implement Q-Learning algorithms with Unity ML-Agents in Colab.     |
+| [Using Side Channels on a UnityEnvironment](https://colab.research.google.com/github/Unity-Technologies/ml-agents/blob/release_22_docs/colab/Colab_UnityEnvironment_3_SideChannel.ipynb)  | Explore side channel communication between Unity and Python.       |