Update relase highlights

Author: swallez

docs/release-notes/release-highlights.asciidoc

@@ -5,6 +5,25 @@ These are the important new features and changes in minor releases. Every releas
 
 For a list of detailed changes, including bug fixes, please see the https://github.com/elastic/elasticsearch-java/releases[GitHub project realease notes].
 
+[discrete]
+==== Version 8.10
+
+* Add instrumentation API and native OpenTelemetry implementation - https://github.com/elastic/elasticsearch-java/pull/588[#588], <<opentelemetry,docs>>
+
+[discrete]
+==== Version 8.9
+
+* Refactor RestClientTransport to allow using other http client libraries - https://github.com/elastic/elasticsearch-java/pull/584[#584]
+
+[discrete]
+==== Version 8.8
+
+* Throw a TransportException when an error response cannot be parsed - https://github.com/elastic/elasticsearch-java/pull/579[#579]
+* Speed up URL path encoding and remove dependency on httpclient - https://github.com/elastic/elasticsearch-java/pull/576[#576]
+* Add buffered lookahead and JsonData implementation for Jackson - https://github.com/elastic/elasticsearch-java/pull/489[#489], https://github.com/elastic/elasticsearch-java/pull/567[#567]
+* Expose additional BulkIngester metrics - https://github.com/elastic/elasticsearch-java/pull/513[#513]
+* Allow unparsed binary data to be used for ingestion - https://github.com/elastic/elasticsearch-java/pull/508[#508]
+
 [discrete]
 ==== Version 8.7