Adding comment to README.md, updating yamato config, and updating Index.md

.yamato/upm-ci-full.yml

   agent:
     type: Unity::VM
     image: cds-ops/ubuntu-18.04-agent:stable
-    flavor: b1.medium
+    flavor: b1.small
   interpreter: python
   commands:
     - cd com.unity.perception/Documentation~

README.md

+[//]: # (Exclude from Index.md)
+
+[//]: # (Note: If you make changes to this file, run com.unity/perception/Documentation~/UpdateIndexMd.py to regenerate Index.md. This is enforced in Yamato.)
+
+[//]: # (End Exclude)
+
 <img src="com.unity.perception/Documentation~/images/unity-wide.png" align="middle" width="3000"/>
 
 <img src="com.unity.perception/Documentation~/images/banner2.PNG" align="middle"/>

com.unity.perception/Documentation~/Index.md

+
+
 <img src="images/unity-wide.png" align="middle" width="3000"/>
 
 <img src="images/banner2.PNG" align="middle"/>
 
 > com.unity.perception is in active development. Its features and API are subject to significant change as development progresses.
 
-BAD CONTENT
 
 # Perception Package ([Unity Computer Vision](https://unity.com/computer-vision))