[Tails-l10n] [fr](review) doc, support, install

Hello, please review.

Repo: https://git-tails.immerda.ch/xin/tails/
Branch: translate/doc2
Last Commit: a657af6c0f3871a35f5751225a4ddd38707795d5

It include:
doc/anonymous_internet/i2p.fr.po
doc/first_steps/startup_options.fr.po
install/inc/steps/install_final.inline.fr.po
install/inc/steps/not_at_all.inline.fr.po
install/inc/steps/restart_first_time.inline.fr.po
install/inc/steps/restart_second_time.inline.fr.po
support/known_issues

Cheers.
xin