Allow a grace period slider for the tab audio function

[PikaDude]

Instead of resuming the audio nearly instantly after a tab stops playing audio, introducing a slider that will allow the user to adjust how long it waits before resuming has been a requested feature.

[jordigarcl]

What would this grace period range be like? I guess seconds, right?

Chrome (on macOS, at least) reports that a tab has stopped playing audio with a 2(-ish) second delay. I find the value to be sensible enough. Of course, allow users to customise is always good.

[RokonShimo]

maybe some sort of fade-in? Going from 20% or 0% volume directly to 100% can be jarring.

[MaxSchaefer]

Should we also add a option to fade out the audio if a tab has started playing?