Features

* ✨ Allow setting the `response_class` to `RedirectResponse` or `FileResponse` and returning the URL from the function. New and updated docs are in the tutorial section **Custom Response - HTML, Stream, File, others**, in [RedirectResponse](https://fastapi.tiangolo.com/advanced/custom-response/#redirectresponse) and in [FileResponse](https://fastapi.tiangolo.com/advanced/custom-response/#fileresponse). PR [#3457](https://github.com/tiangolo/fastapi/pull/3457) by [@tiangolo](https...