Simple window.ai wrapper library in TypeScript

[alexanderatallah]

We need a simple library in packages/ that can be consumed by the extension and web apps. It should:

• be the source of truth for types, e.g. what the extension's public-interface.ts file does today
• allow developers to get types easily when making window.ai apps
• be very simple. Projects like https://github.com/haardikk21/wanda should be able to build on top of it
• throw ErrorCodes appropriately
• add an ErrorCode for when the extension is not installed (wait for a little bit after the document onload event before deciding)
• include examples of usage

[cfortuner]

Started work on this here https://github.com/alexanderatallah/window.ai/pull/17

Got this package -> https://www.npmjs.com/package/window.ai

[alexanderatallah]

Resolved by #17 - big thanks to @louisgv and @cfortuner, we now have an official lib! 📚