Support configuring amount of displayed months

[d-koppenhagen]

Is your feature request related to a problem? Please describe.
It would be great if there is an configuration option that allows to display more than one month when the calendar is opened (e.g. two or three months in a row.).

Describe the solution you'd like
See above.

Describe alternatives you've considered

Additional context

[WickyNilliams]

Hey, I'm the original author of this project. I've made a spiritual successor to duet here. It's not a full date picker (there's a guide in the docs how to do that), but it supports multiple months as well as date ranges. https://github.com/WickyNilliams/cally