Adds french translation file

[alemangui]

Fixes #

Description of the Change

I have added the french translation file.

Checklist

• PR only contains one change (considered splitting up PR)
• unit-test added
• documentation updated
• CHANGELOG.md updated (only for user relevant changes)
• author name in AUTHORS

[codecov]

Codecov Report

Merging #1163 (cc6adda) into master (0f18817) will not change coverage.
The diff coverage is n/a.

@@ Coverage Diff @@## master #1163 +/- ## ======================================= Coverage 96.90% 96.90% ======================================= Files 31 31 Lines 1812 1812 ======================================= Hits 1756 1756 Misses 56 56 

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[n2ygk]

Thanks for this. See the suggestion.