Multi-language docs (i18n)

Add i18n to serve the same docs in several languages with clean prefixed URLs (the default locale unprefixed, others /<locale>/…), a language switcher in the header, hreflang alternates, and per-page chrome — a French page renders French nav, buttons and dates.

i18n: { locales: ["en", "fr"], defaultLocale: "en", strategy: "directory" },

notabene i18n: pick a language from the header switcher, docs and chrome switch

Two authoring layouts

Pick how the files are laid out with strategy:

directory (default) — a folder per locale: docs/en/guide.md · docs/fr/guide.md.
suffix — one tree, translated per file: docs/guide.md (default) · docs/guide.fr.md. Best for adding languages to an existing doc: the default-language files don’t move, so their URLs and their comment threads are preserved.

Language preference & fallback

The switcher records the visitor’s chosen language; from then on, landing on a page written in another language that has a translation redirects to it — following any link keeps you in your language. A page with no translation falls back to the source language and shows a discreet banner. The pages not tied to a content language — /comments, /journal, /review, the home page and 404 — follow your current language client-side and carry the same switcher.

Per-language everything

Comments are per language — a comment on the FR page is its own thread, mapping to the FR source file.
Search and PDF export (notabene pdf --locale fr) are scoped to one language; a public site ships per-locale llms.txt and Markdown twins.
Every human string of the config accepts a per-locale map: a space’s label/description (label: { en: "Docs", fr: "Documentation" }), the custom home page (home: { en: …, fr: … }), and every navigation link label, sidebar block title and footer line. Unset for a locale → it falls back to the default one.

Omit i18n for a single language — behavior is unchanged.