contrib: Introduce nitiwiki

INtroduce nitiwiki base concepts.

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitiwiki: implements html generation.

nitiwiki can now render wiki in html

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitiwiki: add the main executable

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitiwiki: add a test wiki for basic testing

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitiwiki: add custom tests

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitiwiki: nitiwiki is now tested by nit/tests/tests.sh

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitiwiki: add README

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitiwiki: add Makefile

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitiwiki: added default skeletton

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitiwiki: add nitiwiki help page as example

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitiwiki: add out/ directories to gitignore list

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitiwiki: add nitiwiki to listfull.sh

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
src: rename old `markdown` module in `docdown` to avoid merge conflicts

The old markdown module will disappear in a further PR.

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>