[Tails-l10n] [fr](review) usb-image

Hello, it's a first step for the translation of feature/15292-usb-image.
I only do simple changes.

Please review.

Repo: https://git-tails.immerda.ch/xin/tails/
Branch: translate/usb-image
Last Commit: 60e73ff13d2fd7dfebb85d9827c0c3eb802390de

Cheers.
xin