[Feature Request] Document PiP #975

As of Chromium v116, the documentPictureInPicture.requestWindow() method was added, which allows to embed not just the video but any element in the PiP window, this could be useful for subtitles because they stay behind when the PiP button is pressed.

I understand this is a client-side change so it will be possible to accomplish from channel custom JS, but it could still be the default behavior of the video player.

Additional info:
VideoJS demo by Chrome devs (source code)
Official documentation
WICG Explainer