Update to the introduction to the CG

Hi, 

I've slightly updated the Introduction to the W3C BD Comics Manga CG to better reflect the way we could work in a structured manner. 

The proposal is to:
1/ select a use-case, i.e. a style of graphical expression or a trend that is clearly recognized by authors and readers. The first use-cases that come to my mind are "Webtoon", "digitized work", "Turbomedia" ...
2/ define the characteristic UX features of each use-case; e.g. "Scroll" for "Webtoon". Webtoon has very simple features, other use-cases may have a larger set of features. For each feature, define the characteristics authors will need to deal with, and the limit cases the will have to face with. 
3/ give some pointers (on the Web if possible) to pre-existing works representing each use-case and feature and comment them. For Webtoons, they is a quasi infinite number of examples on Line Webtoon, but also new samples on a new French platform name Webtoon Factory. 

Please give some feed back on this process. Are you comfortable with it? 
If yes we will plan our sessions so that we study these different use-cases, from the simple ones (Webtoon seems great as a start) to more complex ones. 

Cordialement, 

Laurent Le Meur
EDRLab