Is there a automatic included "--help" command to print all subcommands ?

I want to print all my subcommands or all commands in total, like a typical "--help" command does in most apps.
I actually need this as a string, so i can send it to my client which actually inputs the commands.

Is something like this already included ? Or do i need to craft this by myself, if so... how ?
Glad for any help due to the lack of documentation and the beta guide couldnt help me either.