* Added doomsday algorithm
* Adding unit-tests to doomsday algorithm
* running black on doomsday
* adding doctest and fixing a black issue [doomsday]
* Update doomsday.py
* fixing black issue [doomsday]
* Update other/doomsday.py
* Update doomsday.py
* adding more doctests (following review comment) [doomsday]
Co-authored-by: John Law <johnlaw.po@gmail.com>
