Add an Attachment type to axum-extra (#2789)

axum/src/boxed.rs

@@ -103,6 +103,7 @@ where
     }
 }
 
+#[allow(dead_code)]
 pub(crate) struct MakeErasedRouter<S> {
     pub(crate) router: Router<S>,
     pub(crate) into_route: fn(Router<S>, S) -> Route,

axum/src/docs/routing/nest.md

@@ -181,7 +181,7 @@ router.
 # Panics
 
 - If the route overlaps with another route. See [`Router::route`]
-for more details.
+  for more details.
 - If the route contains a wildcard (`*`).
 - If `path` is empty.
 

axum/src/json.rs

@@ -17,8 +17,7 @@ use serde::{de::DeserializeOwned, Serialize};
 ///
 /// - The request doesn't have a `Content-Type: application/json` (or similar) header.
 /// - The body doesn't contain syntactically valid JSON.
-/// - The body contains syntactically valid JSON, but it couldn't be deserialized into the target
-/// type.
+/// - The body contains syntactically valid JSON, but it couldn't be deserialized into the target type.
 /// - Buffering the request body fails.
 ///
 /// ⚠️ Since parsing JSON requires consuming the request body, the `Json` extractor must be