docs: update router::route multiple methods docs (#2051)

Co-authored-by: David Pedersen <david.pdrsn@gmail.com>

axum/src/docs/routing/route.md

@@ -61,7 +61,7 @@ the path `/foo/bar/baz` the value of `rest` will be `bar/baz`.
 
 # Accepting multiple methods
 
-To accept multiple methods for the same route you must add all handlers at the
+To accept multiple methods for the same route you can add all handlers at the
 same time:
 
 ```rust
@@ -80,6 +80,23 @@ async fn delete_root() {}
 # let _: Router = app;
 ```
 
+Or you can add them one by one:
+
+```rust
+# use axum::Router;
+# use axum::routing::{get, post, delete};
+#
+let app = Router::new()
+    .route("/", get(get_root))
+    .route("/", post(post_root))
+    .route("/", delete(delete_root));
+#
+# let _: Router = app;
+# async fn get_root() {}
+# async fn post_root() {}
+# async fn delete_root() {}
+```
+
 # More examples
 
 ```rust