document.title was already set from the siteName string, but a
visible #site-title header link stayed hardcoded in whatever language
it was typed in — a translated site showed a translated tab title
next to an untranslated header. Set once in router.js's init() rather
than showListView(), so a page that loads straight into an article
route still gets it. Documented #site-title as optional embedding
markup and corrected README's claim that <title> isn't JS-templated.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>