Update the management documentation for TypeDB Cluster

[lolski]

We should document the "authentication" and "encryption" features in the docs. They should be located under the "Management" section.

Authentication The authentication page should cover the following:

1. How does the authentication work
2. How to manage user accounts (creating, viewing, updating, and deleting)

Encryption The encryption page should cover the following:

1. How does the encryption work: a. For external communication, ie., client-server - using the development certificate - using self-generated certificate - using one generated by established providers such as letsencrypt.org b. For internal communication, ie., between one server to another)
2. How to configure / generate the certificate for external communication
3. How to configure / generate the certificate for internal communication

[izmalk]

Is there a link to some PR/Milestone with auth and encryption added?

[alexjpwalker]

Is there a link to some PR/Milestone with auth and encryption added?

I'm not quite sure what you mean by this, sorry!