* Change `HeaderMap` extractor to clone the headers
* fix docs
* changelog
* inline variable
* also add changelog item to axum
* don't list types from axum in axum-core's changelog
* document that `HeaderMap::from_request` clones the headers
* fix typo
* a few more typos
* Move `IntoResponse` to axum-core
* Move `FromRequest` to axum-core
* some clean up
* Remove hyper dependency from axum-core
* Fix docs reference
* Use default
* Update changelog
* Remove mention of default type