createCalendarPolicy
fun createCalendarPolicy(weeklyOffDays: Array<Int>, events: Array<NepaliEvent>): NepaliCalendarPolicyInfo(source)
A policy over weeklyOffDays (1 for Sunday through 7 for Saturday) and events.
Nepal's office week is [7]; a school closed Saturday and Sunday is [7, 1]; [] is an institution that never closes for the week alone. A number outside 1..7 throws, since a set written to JavaScript's own 0-based weekday convention would otherwise close nothing at all.