move from mardkown to ascii doc

[allan-simon]

This is rather an important change, and needs to be discussed but I see the following advantages:

• Asciidoc is well defined, and does not have the dozen of dialects that has markdown, which mean the javascript renderer will render the same things as a "server side renderer" (or it's a bug, not a "well markdown does not define really that" or "yeah but this javascript library implement this or that extensions" )
• Asciidoc supports much more things than "pure" markdown (table anyone ?)
• Asciidoc has a very nice "browser editor" https://github.com/cmoulliard/asciidoc-ace-editor https://github.com/angular-ui/ui-ace , with bower package and so on, which help managing dependency
  • Asciidoc has a nice toolset for producing not only HTML, but also pdf, ebooks etc. which would make tatowiki suitable for the collaborative redaction of ebooks
• it would be not "impossible" to convert existing "markdown" articles into asciidoc (as I guess most of the Taoteba's instance of tatowiki does not use complex structures nor specific extensions ?