[NTG-context] french translation of ConTeXt interface - progress (v3)

[Garulfo]

> And, if it makes sense for ConTeXt's community to use it as a "new" or 
> an "updated" french interface, I may try to produce a 40~50 pages 
> documentation for the basics commands (during 2020 S2):

or even better, I will try to use Paul + Taco + Wolfgang documentation 
framework through the wiki.