drafts available

Hi all,

We discussed this at the F2F last week and I wanted to paste a link here for everyone to see and comment on:
https://github.com/w3c/sync-media-pub/blob/master/manifest-exts.md <https://github.com/w3c/sync-media-pub/blob/master/manifest-exts.md>

It covers two key concepts:
- how to represent the audio + text sync points 
- how to integrate all this into a web publications manifest

Thanks to Daniel Weck for putting this together. Looking forward to some good discussions.

Marisa