[zanata] Zanata integration
For now, french versions are used to push to Zanata. When they're good enough to stop modify them, we will translate to english, then use english version to push to Zanata.
This MR:
- splits configuration file in multiple files to be able to translate them
- adds a Makefile to ease the use of hugo with multiple files and the use of Zanata
- update
content/faq.fr.md
to be able to translate simple sentences in Zanata, (almost) without HTML tags in it.