minor match-3 doc updates (#4653)

* updated image in learning envs examples

* add link to learning example to match-3

* cleaned up headings

* removed anchor

* Update Match3.md

* Delete match3.png

* added new match3 image

* updated match3 image link

com.unity.ml-agents.extensions/Documentation~/Match3.md

 This implementation includes:
 
 * C# implementation catered toward a Match-3 setup including concepts around encoding for moves based on [Human Like Playtesting with Deep Learning](https://www.researchgate.net/publication/328307928_Human-Like_Playtesting_with_Deep_Learning)
-* An example Match-3 scene with ML-Agents implemented (located under /Project/Assets/ML-Agents/Examples/Match3)
+* An example Match-3 scene with ML-Agents implemented (located under /Project/Assets/ML-Agents/Examples/Match3). More information, on Match-3 example [here](https://github.com/Unity-Technologies/ml-agents/tree/release_10_docs/docs/docs/Learning-Environment-Examples.md#match-3).
+### Feedback
-## Interested in more game templates?
+### Interested in more game templates?
 Do you have a type of game you are interested for ML-Agents?  If so, please post a [forum issue](https://forum.unity.com/forums/ml-agents.453/) with [GAME TEMPLATE] in the title.
 
 ## Getting started

docs/Learning-Environment-Examples.md

 - Benchmark Mean Reward: 1.75
 
 ## Match 3
-
 ![Match 3](images/match3.png)
 
 - Set-up: Simple match-3 game. Matched pieces are removed, and remaining pieces