[Feature] Add a countdown/days until widget

[Perverance]

Something that would let you choose a specific date or number of days, and display a widget with a custom label and the remaining days, and maybe a circular progress bar.

It's just an idea I'd love to see. Thank you!

[gonzalrick]

Hi @Giulidan, there is an open pull request for a countdown widget https://github.com/joelshepherd/tabliss/pull/511