trigger help via subcommand

[theoephraim]

Clear and concise description of the problem

Would like to be able to trigger help via mycli help as well as mycli --help

Suggested solution

Could either be a manual thing where I manually define a help subcommand and then programatically call a function which shows the help info, or could be a top level option which automatically enables a help subcommand.

Alternative

No response

Additional context

No response

Validations

• Read the Contributing Guide.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.