Add repeat-with-delay

[malsyned]

Traditional key repeat has a delay before the first repetition that's different than the delay between subsequent repeats. I would love if turbo and relconst added the ability to specify an initial delay before the repeats started.

My specific use case is remapping the Basilisk V2's DPI Up/Down buttons to scroll up and down by a large amount (6 or so). I'd love to set a repeat of 33ms to start after a delay of 250ms.