Translate untranslated strings in French (fr) locale

[colinkiama]

The French locale file at .vitepress/locales/fr.js has the following keys still left in English and need translating:

• go_home: "Go Home"
• current_versions: "Current Versions"
• install_how: "How to install"
• stable: "Stable"
• stable_lts: "Stable Long-term Support"
• devel: "Development"
• roadmap: "Roadmap"

You can compare against .vitepress/locales/en.js for the English source text.