[Tails-l10n] [fr](Review) wiki/src/install

Hello, I begin to translate the installation assistant.
It's very long. I made a first commit.
I should send more after the merge of this commit.
Please review.

Repo: https://git-tails.immerda.ch/xin/tails/
Branch: translate/installassistant
Commit: daa62ad7b32a3472ffa87874e7f961a77866f114

Cheers.
xin