Annotations TF: Use case update PR

Hello, 

Following our last meeting (July 10th) and the last PBG meeting (July 29th) I updated the Use Case document with new use cases and some evolutions on the wording of existing ones. 

You can review the Pull Request here https://github.com/w3c/epub-specs/pull/2767, before I merge it. 

The next phase is to extract the best use cases from older documents.  

Please review the use cases and issues relative to older initiatives, on:
- DPUB Annotations:  https://w3c.github.io/dpub-annotation/
- Publishing CG issues: https://github.com/w3c/publishingcg/issues?q=is%3Aissue%20label%3A%22Topic%3A%20selector%20or%20annotation%22
- Video form an interview of George Kercher, Social Learning Across Content: https://www.youtube.com/watch?v=8N0lvdIC4cQ&list=PLmuJEyeapl2frN3x1jXRS35GiyM7fM2aY&t=388s
- Web Annotations, UCR: https://www.w3.org/2008/WebVideo/Annotations/wiki/Use_Cases_%26_Requirements.html
- Web Annotations, Wiki: https://www.w3.org/annotation/wiki/Use_Cases

Plus, the set of documents Ivan provided to the TF in an email to the TF mailing list, on July 2nd
[1] https://www.w3.org/2014/04/annotation/
[2] https://www.w3.org/2014/04/annotation/report
[3] https://www.w3.org/2014/04/annotation/slides/SharingAndContributing_SBoisen.pdf
[4] https://www.w3.org/2014/04/annotation/slides/Gerber-ScholarlyAnnotationLightning.pdf
[5] https://www.w3.org/2014/04/annotation/slides/williamson.pdf
[6] https://www.w3.org/2014/04/annotation/slides/gerardo-slides.pdf

... Some work for the summer, isn't it :-) ?

A reminder: the minutes of our meetings are stored on https://w3c.github.io/pm-wg/minutes/#ann. 

Another information: the group of interested parties is currently:
EDRLab
Readium Foundation
Colibrio
FBReader
Zotero
Readwise
We are still looking for an official expression of interest from other W3C members. 
I'll also contact the developers of successful mobile EPUB readers (+10M downloads) with annotation support, like Moon+ Reader, ReadEra, eBoox, KoReader. 

Best regards
Laurent