CalendarCommandForKey#
func CalendarCommandForKey(key ui.Key, modifiers ui.Modifiers) (CalendarCommand, bool)CalendarCommandForKey maps the keys of a focused day to the move they ask for: the arrows move by day and week, PageUp and PageDown by month (by year with Shift), Home and End to the edges of the week. Left and Right follow the reading direction only if the caller flips them for right-to-left text.