Add an error message for range mmmm.yy.dd MMMM.YY.DD when mmmm.yy.dd > MMMM.YY.DD

[hiAndrewQuinn]

$ python main.py range 2024.04.23 2024.04.21

currently outputs nothing at all, and creates a nonempty cards.apkg file. This can confuse a newcomer, especially one used to the old-fashioned Unix way of "silence implies success". Much better would be something like

python main.py range 2024.04.23 2024.04.21
[Error] Start date 2024.04.23 is greater than end date 2024.04.21.

This could be implemented in the typer part of the command itself. No need to do complicated error checking logic elsewhere, this is just basic input validation.