Update docs/Training-Self-Play.md

Co-Authored-By: Vincent-Pierre BERGES <vincentpierre@unity3d.com>

docs/Training-Self-Play.md

 
 ![Team ID](images/team_id.png)
 
-***Team ID must be 0 or an integer greater than 0. Negative numbers will cause unpredictable behavior.*** See the trainer configuration and agent prefabs for our Tennis environment for an example.
+***Team ID must be 0 or an integer greater than 0. Negative numbers will cause unpredictable behavior.*** 
+See the trainer configuration and agent prefabs for our Tennis environment for an example.
 
 ## Best Practices Training with Self-Play