Add a date selector option

[andreagrax]

Is your feature request related to a problem? Please describe.
It would we useful to add a date selector

Describe the solution you'd like
something like gum calendar that shows a calendar from where the user can select the date

Describe alternatives you've considered

creating the input with cal and passing it to gum, but it's definitely messy

[bashbunni]

Hey, thanks for reaching out! Given that Gum is a wrapper for Bubbles, I've linked the PR for the calendar component over there. Once that's merged, then we can look at integrating something similar for Gum :)

Related: charmbracelet/bubbles#475