[Internal]: Document the kibana "Management" permissions

### Description

The kibana privileges in the "Management" section are not documented in a centralized way. For some of them, it's not obvious what they do. It would be helpful when defining a role's privileges to have a centralized page that describes what each privilege does, and if applicable links to related feature docs.

### Resources

Some discussion [here](https://elastic.slack.com/archives/C02FR8NGS2E/p1762277503275489)

### Which documentation set does this change impact?

Elastic On-Prem and Cloud (all)

### Feature differences

This would involve figuring out any differences between different deployment methods

### What release is this request related to?

N/A

### Serverless release

-

### Collaboration model

The documentation team

### Point of contact.

**Main contact:** @

**Stakeholders:**

## Action
added by (@georgewallace)

- Determine what each permission actually means (work with someone in engineering)
- Consider a configuration reference for each permission... or add to this documentation