Ability to add child teams

As title says 🙂

It would be advantageous if this bot could support nesting Teams.

The team sync yaml could be enhanced to support something like the following:

```yml
# This property is used to control the addition of general Members to your Organization.
OrganizationMembersGroup: Some_Group_To_Sync_For_Organization_Membership
# This property is used for syncing all other GitHub Teams. Please note that users must also be a part of the `OrganizationMembersGroup` for the synchronization of the teams below to function properly.
GitHubTeamNames:
- Team: Some_Team_To_Sync
FollowChildren: true
- Team: Some_Other_Team_To_Sync
Children:
- Team: Some_Child_Team_To_Sync
Children: Some_Child_Team_To_Sync
- Some_Other_Child_Team_To_Sync
```

L’issue ne nomme aucun fichier source, test ni point d’entrée. Commencez par localiser la configuration YAML de synchronisation des équipes et le code qui traite GitHubTeamNames ; définissez le comportement attendu de Children et FollowChildren imbriqués, puis vérifiez que les équipes imbriquées se synchronisent comme prévu.

Rédigé par le modèle d'indexation à partir du texte de l'issue.