Setup Internationalization

[neatonk]

The UI will be designed to support multiple languages.

References:

• https://nextjs.org/docs/app/building-your-application/routing/internationalization
• https://github.com/vercel/next.js/blob/canary/examples/app-dir-i18n-routing
• https://github.com/supabase/auth-ui/blob/2ff64af7109c0c9d37d046bd8c8cc21816a511ee/packages/shared/src/localization/en.json