Add translations for `proposals.community_translations`

[smorimoto]

Translation status of each language

At the time this issue was created, work has already been completed in French and Russian, but not yet in the other languages. Anyone interested in working on this, raise your hand on this issue. (To prevent duplication of effort among multiple contributors!)

Language	Status	Link
German Translation	✅	tc39.github.io/de/proposals.json Line 29 in be8c92e "community_translations": "This page is translated by the community. If you want to contribute, read our <a href=\"https://github.com/tc39/tc39.github.io/blob/main/translation_de.md\">guidelines</a>.",
French Translation	✅	tc39.github.io/fr/proposals.json Line 29 in be8c92e "community_translations": "Cette page est traduite par la communauté. Si vous souhaitez contribuer, lisez nos <a href=\"https://github.com/tc39/tc39.github.io/blob/main/translation.md\">directives</a>.",
Japanese Translation	✅	tc39.github.io/ja/proposals.json Line 29 in be8c92e "community_translations": "このページはコミュニティによって翻訳されています。貢献したい場合は、<a href=\"https://github.com/tc39/tc39.github.io/blob/main/translation_ja.md\">ガイドライン</a>をお読みください。",
Russian Translation	✅	tc39.github.io/ru/proposals.json Line 29 in be8c92e "community_translations": "Эта страница переведена сообществом. Если Вы хотите сделать вклад, прочитайте наши <a href=\"https://github.com/tc39/tc39.github.io/blob/main/translation_ru.md\">гайдлайны</a>.",
Simplified Chinese	✅	tc39.github.io/zh-Hans/proposals.json Line 29 in be8c92e "community_translations": "这个页面的翻译是由社区贡献的。如果你也想贡献，请阅读我们的<a href=\"https://github.com/tc39/tc39.github.io/blob/main/translation_zh-Hans.md\">指引</a>。",

[Ritish134]

Hi there would like to work on this issue can you assign it to me

[0xDevNinja]

Hi maintainers — quick audit on main: every locale's proposals.json already has a translated community_translations value (no English placeholder remains). It looks like this issue is now stale.

Locale	community_translations excerpt
de	"Diese Seite wird durch die Allgemeinheit übersetzt…"
fr	"Cette page est traduite par la communauté…"
ja	"このページはコミュニティによって翻訳されています…"
ru	"Эта страница переведена сообществом…"
zh-Hans	"这个页面的翻译是由社区贡献的…"
uk	"Ця сторінка перекладена спільнотою…"

A few of the historical commits where translations landed, for reference:

• e812c7a — French translation
• f942934 — Russian translation additions (Sergey Rubanov)
• ce9b9f6 — Add more translations for ja/proposals.json
• 4b9d3aa — Updated German translation
• 7ddb60d — Introduce the Ukrainian language
• c70476e — Eleventy migration (Eleventy migration #269), which carried the zh-Hans value forward

Since all listed locales (and the later-added uk) are now covered, would it be reasonable to close this issue as completed? Happy to follow up if anything is missed.