Update ReleaseNotes.md

Author: chkr1011

.github/workflows/ReleaseNotes.md

@@ -1,3 +1,4 @@
+* [Client] Exposed the _EndPoint_ type to support other endpoint types (like Unix Domain Sockets) in client options (#1919).
 * [Server] Added new events for delivered and dropped messages (#1866, thanks to @kallayj).
 * [Server] The server will no longer treat a client which is receiving a large payload as alive. The packet must be received completely within the keep alive boundaries (BREAKING CHANGE!, #1883).
 * [Server] Fixed "service not registered" exception in ASP.NET integration (#1889).