This adds date dividers if none are entered.
It also adds the current year if it wasn't entered.
This allows users to just enter 1003, 100322, 10032022 and
have it expanded to 10.03.2022, in the case of the German format.
(All other formats are also supported)
It also replaces commas with the date divider.
This allows quick entry of the date on the numpad.
Ensure that no source files have trailing whitespace at end of lines and ensure that all files end with a single trailing newline.
This also adds Github Actions to enforce whitespace conventions.
