Update release notes.

Author: ioquatix

releases.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
-### Remove Priority Frame and Dependency Tracking
+### Added Priority Update Frame and Stream Priority
 
-HTTP/2 has deprecated the priority frame and stream dependency tracking. This feature has been effectively removed from the protocol. As a consequence, the internal implementation is greatly simplified. The `Protocol::HTTP2::Stream` class no longer tracks dependencies or priorities, and this includes `Stream#send_headers` which no longer takes `priority` as the first argument.
+HTTP/2 has deprecated the priority frame and stream dependency tracking. This feature has been effectively removed from the protocol. As a consequence, the internal implementation is greatly simplified. The `Protocol::HTTP2::Stream` class no longer tracks dependencies, and this includes `Stream#send_headers` which no longer takes `priority` as the first argument.
+
+Optional per-request priority can be set using the `priority` header instead, and this value can be manipulated using the priority update frame.