Koa v3 Tracker
Starting a new tracker for v3

Milestone: https://github.com/koajs/koa/milestone/4

Other Breaking Changes:

- [ ] rewrite to ES modules
- [ ] adjust naming to WHATWG standards https://nodejs.org/api/url.html#url_url_strings_and_url_objects
- [ ] rename raw http requests? https://github.com/koajs/koa/issues/1114#issuecomment-405937240
- [ ] officially support the http2 module

Future:

- [ ] Deno support
- [ ] Bun support
- [ ] Rewrite in TypeScript

Tests:

- [x] Migrate to jest
- [x] Properly close down server after each test run

Improved Documentation:

- [x] how to serve http/https/http2
- [ ] example of how to use expect-continue
- [ ] https://github.com/koajs/koa/discussions/1827
- [x] https://github.com/koajs/koa/discussions/1774 SSE example with AI chat