[MSE] MPEG audio byte stream format spec.

I just wanted to let people know that I just posted a draft of the MPEG
audio byte stream format
spec<https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/mpeg-audio-byte-stream-format.html>
that
Chrome has been experimenting with for a while. It allows MP3 & ADTS
streams to be used with MSE.

Assuming that there are no major objections, I'd like to add it to the byte
stream format registry<https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/byte-stream-format-registry.html>
in
the next week or two.

Aaron