Ability to stop parsing flags when -- is passed in

[PurpleMyst]

Is your feature request related to a problem?

I'd like to be able to stop parsing flags, so I'd be able to do stuff like my-cmd foo bar -- --baz and they'd all be passed as positional arguments.

Describe the solution you'd like

As I've said, "--" passed as an argument should mean to not parse any more non-positional arguments.

Describe alternatives you've considered

There's no alternative solution that I've found within the current argh framework.

Additional context

This is canonical from GNU/POSIX getopt.