• changed: The inner error of a JsonRejection is now
  serde_path_to_error::Error<serde_json::Error>. Previously it was
  serde_json::Error (#1371)
• added: JsonRejection now displays the path at which a deserialization
  error occurred too (#1371)
• fixed: Support streaming/chunked requests in ContentLengthLimit (#1389)
• fixed: Used 400 Bad Request for FailedToDeserializeQueryString
  rejections, instead of 422 Unprocessable Entity (#1387)
• added: Add middleware::from_extractor_with_state and
  middleware::from_extractor_with_state_arc (#1396)
• added: Add DefaultBodyLimit::max for changing the default body limit (#1397)
• added: Add map_request, map_request_with_state, and
  map_request_with_state_arc for transforming the request with an async
  function (#1408)
• added: Add map_response, map_response_with_state, and
  map_response_with_state_arc for transforming the response with an async
  function (#1414)
• breaking: ContentLengthLimit has been removed. Use DefaultBodyLimit instead (#1400)
• changed: Router no longer implements Service, call .into_service()
  on it to obtain a RouterService that does (#1368)
• added: Add Router::inherit_state, which creates a Router with an
  arbitrary state type without actually supplying the state; such a Router
  can't be turned into a service directly (.into_service() will panic), but
  can be nested or merged into a Router with the same state type (#1368)
• changed: Router::nest now only accepts Routers, the general-purpose
  Service nesting method has been renamed to nest_service (#1368)
• added: Support compiling to WASM. See the simple-router-wasm example
  for more details (#1382)
• breaking: New tokio default feature needed for WASM support. If you
  don't need WASM support but have default_features = false for other reasons
  you likely need to re-enable the tokio feature (#1382)
• breaking: handler::{WithState, IntoService} are merged into one type,
  named HandlerService (#1418)
• changed: The default body limit now applies to the Multipart extractor (#1420)
• added: String and binary From impls have been added to extract::ws::Message
  to be more inline with tungstenite (#1421)
• added: Add #[derive(axum::extract::FromRef)] ([#1430])
• added: FromRequest and FromRequestParts derive macro re-exports from
  [axum-macros] behind the macros feature (#1352)
• breaking: MatchedPath can now no longer be extracted in middleware for
  nested routes (#1462)
• added: Add extract::RawForm for accessing raw urlencoded query bytes or request body (#1487)
• breaking: Rename FormRejection::FailedToDeserializeQueryString to
  FormRejection::FailedToDeserializeForm (#1496)