Words the digest emails share with the pages that show or govern them: the
/community page shows the digests' figures and sections, Settings and the
unsubscribe page name the digests, the avatar menu links the community
page. api/mail/digest.ts and those pages translate them from here, so an
email and a page always say the same.
Each is a Lingui message descriptor with an explicit id, since the server
runs no macro; the i18n comment has lingui extract read its English into
the catalogs. Pass one to i18n._, with its values: on the client, the
i18n of useLingui().
Usage
import * as mod from "shared/digest-messages.ts";