As a Jira Admin,
I want to enter org-wide days off only once, and share them across all teams,
So that I do not have to enter the same set on each Agile Board.

AC:
A. In a central config, enter Standard Working Days once org-wide.
B. In a central config, enter Non-Working Days once org-wide.
C. On any Agile Board, optionally include org-wide Standard Working Days.
D. On any Agile Board, optionally include org-wide Non-Working Days.
E. On any Agile Board, optionally include extra or override one-off Standard Working Days (per current feature).
F. On any Agile Board, optionally include extra or override one-off Non-Working Days (per current feature).

-Johnny