[Tails-l10n] [Review](fr) Many translation to review

Hi,

please review updated or brand new translations for Tails website:

wiki/src/doc/first_steps/installation.fr.po
wiki/src/doc/first_steps/installation/manual/mac.fr.po
wiki/src/doc/first_steps/introduction_to_gnome_and_the_tails_desktop.fr.po
wiki/src/doc/first_steps/upgrade.fr.po
wiki/src/news/spoof-mac.fr.po
wiki/src/support/known_issues.fr.po

commit 833c0a0, translation branch, mercedes508 repo.

Cheers.