Create CLI documentation

[SchoolGuy]

Is your feature request related to a problem?

As a user
I want to be able to read extensive documentation
so that I can easier understand how to use the CLI.

Provide a detailed description of the proposed feature

Currently, the CLI documentation is provided on the server ReadTheDocs repository. This is fine since the current built-in CLI is present there. Since the CLI will be maintained in this repository, it would be better to pair the documentation with the tool.

The user guides should stay inside the backend as many of the topics are tightly integrated with the available capabilities of the Cobbler host machine.

Alternatives you've considered

None

Additional information

None