Positional argument specifications

[stevvooe]

I may be missing something in the documentation, but there doesn't seem to be a way to specify positional arguments for each commands. For example, one may want to specify in the help that two arguments are accepted only:

NAME:
   foo - Apply foo to argument bar and optionally a baz

USAGE:
   command foo bar [baz]

This seems like a straightforward addition to the library but I wanted to get feedback before dropping a PR. Python's argparse provides a good example of this done well. Such a feature also provides the benefit that arguments can be pre-validated before proceeding with the command.

[jszwedko]

Work has been started on this over here: #140

[coilysiren]

Given that this is from last year, I think I'm comfortable closing it 🙂 feel free to re-open / open a new issue / comment in support if there's still interest here!