[docs] Fix link and add teams/groups to table of contents (#5126)

Author: Ervin T

docs/Learning-Environment-Design-Agents.md

@@ -30,6 +30,8 @@
 - [Agent Properties](#agent-properties)
 - [Destroying an Agent](#destroying-an-agent)
 - [Defining Multi-agent Scenarios](#defining-multi-agent-scenarios)
+  -[Teams for Adversarial Scenarios](#teams-for-adversarial-scenarios)
+  -[Groups for Cooperative Scenarios](#groups-for-cooperative-scenarios)
 - [Recording Demonstrations](#recording-demonstrations)
 
 An agent is an entity that can observe its environment, decide on the best

docs/ML-Agents-Overview.md

@@ -613,7 +613,7 @@ they result in the individual being removed from the game (i.e., self-sacrifice)
 MA-POCA can also be combined with self-play to train teams of agents to play against each other.
 
 To learn more about enabling cooperative behaviors for agents in an ML-Agents environment,
-check out [this page](Learning-Environment-Design-Agents.md#cooperative-scenarios).
+check out [this page](Learning-Environment-Design-Agents.md#groups-for-cooperative-scenarios).
 
 For further reading, MA-POCA builds on previous work in multi-agent cooperative learning
 ([Lowe et al.](https://arxiv.org/abs/1706.02275), [Foerster et al.](https://arxiv.org/pdf/1705.08926.pdf),