Fossify Calendar - Option to choose how many Weeks are shown in Widget

[WeiTuFat]

An option to customise the Android widget to show only a chosen number of weeks? And which weeks?

For example - options to set the 'monthly view' to 3 weeks, showing last week, current week, next week.

This will help with at-a-glance screen real estate.

[WeiTuFat]

Very similar to https://github.com/FossifyOrg/Calendar/issues/424