Opinion: Arguments should not be required for Variadics

Docs:

• Arguments:
  If you come from argparse, you might be missing support for setting nargs to + to indicate that at least one argument is required.
  This is supported by setting required=True. However, this should not be used if you can avoid it as we believe scripts should gracefully degrade into becoming noops if a variadic argument is empty. The reason for this is that very often, scripts are invoked with wildcard inputs from the command line and they should not error out if the wildcard is empty.

Reasoning:
Beyond the reasoning stated, I don't know of any.

Feature unlocked: N/A

Start by reviewing the Arguments documentation and the variadic argument behavior described here, including required=True and the argparse comparison. Clarify whether the proposal changes runtime semantics or only documents current guidance; done requires an agreed behavior and corresponding documentation and test scope.