[Docs] Team Manager role doesn't have default permissions

### Current State
The [Team Manager Role](https://docs.layer5.io/cloud/concepts/identity-and-security/roles/#team-manager) doesn't have any [default permissions](https://docs.layer5.io/cloud/reference/default-permissions/#Team+Admin) listed.

### Desired State
The default permissions for the role should be listed there.

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#### Contributor Guide and Resources
- 📚 [Instructions for contributing to documentation](https://github.com/layer5io/docs/blob/master/CONTRIBUTING.md)
- Layer5 documentation [site](https://docs.layer5.io) and [source](https://github.com/layer5io/docs/)
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