[Feature Request] Setting custom start of calendar

[cjsjyh]

Hi,
Currently, react-native-calendars only allows initialMonth to be set.
Would it be possible to add an option to set custom start of the calendar? (For Example, 1/20 ~ 2/19)
I want to implement a feature that requires to show a period that goes over the month.

minDate, maxDate doesn't seem to be the solution for my case.
Let me know if i am missing anything.

Thanks!