chore(theme-translations): complete French translations

[forresst]

Pre-flight checklist

• I have read the Contributing Guidelines on pull requests.
• If this is a code change: I have written unit tests and/or added dogfooding pages to fully verify the new behavior.
• If this is a new API or substantial change: the PR has an accompanying issue (closes #0000) and the maintainers have approved on my working plan.

Motivation

Complete translations in French

Test Plan

Test links

Deploy preview: https://deploy-preview-_____--docusaurus-2.netlify.app/

Related issues/PRs

[netlify]

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[github-actions]

⚡️ Lighthouse report for the deploy preview of this PR

URL	Performance	Accessibility	Best Practices	SEO	PWA	Report
/	🟠 70	🟢 97	🟢 92	🟢 100	🟠 89	Report
/docs/installation	🟠 73	🟢 98	🟢 92	🟢 100	🟠 89	Report

[slorber]

Thanks 👍