10.2.3 release notes (#3740)

docs/src/main/paradox/release-notes/10.2.x.md

@@ -1,5 +1,32 @@
 # 10.2.x Release Notes
 
+## 10.2.3
+
+This release includes a working preview HTTP/2 client. Please consider using this preview to provide early feedback in case you find issues in your use-case. The HTTP/2 client will soon be included as an opt-in backend for the Akka gRPC client.
+
+Native HTTP/2 support in Akka gRPC reduces the number of upstream dependencies and enables more deeply integrated tooling for Akka gRPC in the future.
+
+For now, a connection-level and a "persistent connection" API is provided. The entry points are very similar to the existing flow-based HTTP/1 client APIs (responses are provided out-of-order, though, see the docs). The persistent connection API provides functionality similar to the `newHostConnectionPool` API.
+
+Higher-level APIs for HTTP/2 like the `superPool` or `singleRequest` APIs (or a potential automatic integration into the existing APIs) are still discussed.
+
+Please see the @ref[documentation](../client-side/http2.md) for more information and usage examples.
+
+Other notable changes:
+
+#### akka-http-core
+
+* Better support for filename in Content-Disposition [#3705](https://github.com/akka/akka-http/pull/3705)
+* Warn if trying to bind flow/source with HTTP2 (which is not supported) [#3678](https://github.com/akka/akka-http/pull/3678)
+
+#### akka-http-testkit
+
+* Fetch chunks in the testkit without waiting for the whole response to finish [#3724](https://github.com/akka/akka-http/pull/3724)
+
+#### docs
+
+* Show examples of using the Akka HTTP BOM (bill of materials) in dependency blocks
+
 ## 10.2.2
 
 This release includes a number of improvements to the HTTP/2 server support,