Picks the interface's language and loads its messages into Lingui's global
i18n, which the components' t and Trans read. main.tsx calls it once
before rendering.
f
loadCatalog(locale?: Locale): Promise<void>
Loads the messages of locale, the detected one by default, then activates
it and stores it for the next visit. There is no language switch in the
interface yet, so the stored one comes from the browser's language.
Usage
import * as mod from "src/i18n.ts";