More CLI help menus

[mcandre]

Is your feature request related to a problem? Please describe

Please provide command line help menus. I keep having to revert to an Internet connection to remember the correct command syntax.

Describe the proposed solution

-h / --help / help options for all subcommands and flags.

Describe similar asdf features and why they are not sufficient

The ASDF website provides decent documentation, however for convenience and offline use, a conventional usage menu would be more practical.

Describe other workarounds you've considered

Applying alternative version manager systems.