The `supabase-js` library has been updated to version 2, focusing on quality-of-life improvements for developers. The new version includes Type support, new authentication methods, and features such as real-time multiplayer sneak peeks. Additionally, the documentation has been revamped with auto-generated reference docs from TypeScript definitions, placeholders for other languages, and sections for open-source tools like Postgres and GoTrue. This update also introduces a new pattern of handling errors by returning them instead of throwing exceptions, and creates a new library called `gotrue-js` to support Netlify's GoTrue auth server. The update includes native TypeScript support, better real-time scalability, and fixes for minor bugs. However, it does introduce breaking changes such as name changes in some functions and the removal of certain parameters. Users are advised to upgrade to the new version by installing the latest version of `supabase-js`, updating their code to use the new Auth interface, and following the documentation for a smooth transition.