Add release notes for 10.0.10 (#1398)

docs/src/main/paradox/scala/http/release-notes.md

@@ -5,7 +5,40 @@
 ### Support for HTTP(S) proxies with Authorization
 
 It is now possible to connect to @scala[@ref[HTTP(S) Proxies](client-side/client-transport.md)]@java[@ref[HTTP(S) Proxies](client-side/client-transport.md)]
-that require an authorization via an `Proxy-Authorization` header. This can be set up directly on the `ClientTransport` object when configuring the proxy.
+that require an authorization via an `Proxy-Authorization` header. This can be set up directly on the `ClientTransport` object when configuring the proxy. ([#1213](https://github.com/akka/akka-http/issues/1213))
+
+### Documentation for HTTP 2 support (Preview)
+
+Server-side HTTP/2 support, currently available as a preview, has now been
+@ref[included in the documentation](server-side/http2.md)
+([#1297](https://github.com/akka/akka-http/pull/1297)
+
+### Documentation consolidation
+
+Behind the scenes, a lot of work has been done on the ongoing effort to
+consolidate the Java and Scala versions of the documentation, notably
+by
+Jonas Fonseca and Josep Prat. This will make our documentation more consistent,
+higher-quality and more easy to browse and maintain ([#1290](https://github.com/akka/akka-http/issues/1290)
+
+### Improvements
+
+* (server) Better error reporting when failing to handle CONNECT requests ([#1315](https://github.com/akka/akka-http/issues/1315))
+* Add HttpApp.startServer(host, port, system) ([#1294](https://github.com/akka/akka-http/issues/1294))
+* Preserve the order of repeated parameters when retrieving query string as a multimap ([#1270](https://github.com/akka/akka-http/pull/1270))
+* Missing final boundary for empty multipart entities ([#1257](https://github.com/akka/akka-http/issues/1257))
+* Add Cache-Control 'immutable' value ([#1212](https://github.com/akka/akka-http/issues/1212))
+* Http2: Inbound flow control ([#737](https://github.com/akka/akka-http/issues/737))
+
+### Bugfixes
+
+* HttpChallenge rendering is broken if realm parameter is None ([#1295](https://github.com/akka/akka-http/issues/1295))
+* Logging with println in Http2ServerDemux ([#1275](https://github.com/akka/akka-http/issues/1275))
+* Incorrect request URIs with HTTP/2 ([#1274](https://github.com/akka/akka-http/issues/1274)
+* HttpResponseParser returns invalid status code for statuses without reason phrase ([#1251](https://github.com/akka/akka-http/issues/1251))
+* Ensure that no responses are lost when `host-connection-pool.idle-timeout` kicks in ([#1245](https://github.com/akka/akka-http/issues/1245))
+* Large response entity is truncated over https with 'Connection: close' header ([#1219](https://github.com/akka/akka-http/issues/1219))
+
 
 ## 10.0.9