Add the :empty: parameter

[waveform80]

Requested on the original docs to permit list generation for future releases.

[SecondSkoll]

LGTM. Tests fine locally (I should get around to writing tests for this repo properly soon).

[SecondSkoll]

Version updated.

[waveform80]

Thanks! Incidentally, the extension is built so that it should also pass mypy --strict; if you're tweaking the GH actions to run the doctest suite, that could/should probably be added as well.

[SecondSkoll]

I'll probably just implement something basic to start with validate extension functionality - but ai will keep that in mind :)