Push fr release-notes for f23 in stg

[Jean-Baptiste]

Hi there,

Better late than never, can you please push french translation of f23 
release-notes in staging ? (and give the link)

We took this doc to rebuild our team, processes and take Zanata in hand.
It was a good candidate because it has every kind of string to 
translate, some are use for website too.
I assume we should be ready to address f24 release-notes (april 13th to 
april 18th for beta release notes translation, if I correcty read the 
schedule).

Note : there were some useless strings coming from f22 release notes and 
f21 release notes. Strange, but useless to fix now. I'll have a close 
look at f24 release notes to prevent this.

Thanks for your help.