Update docs related to React 18 (#35952)
* update docs of streaming
* add switchable runtime docs
* add page to manifest
* Apply suggestions from code review
Co-authored-by: Steven <steven@ceriously.com>
* Update docs/advanced-features/react-18/streaming.md
Co-authored-by: Lee Robinson <me@leerob.io>
Co-authored-by: Steven <steven@ceriously.com>
