Allow time input to match 12/24 hour setting

[mcg]

Love being able to directly enter a time instead of just using the slider, tho I wish this was more easily accessible(#39), but this issue is not being able to enter 24 hour times. Only 12 hour times are supported. It would be great if the manual time entry field input reflected the 12/24 hour time preference.

[mdeguzis]

https://github.com/n0shake/clocker/issues/39 was closed and this linked, but I still cannot enter a specific time. Is there a docs page on how to do things? The wiki is blank.