Added 2.16 release notes (#52)

Signed-off-by: Chenyang Ji <cyji@amazon.com>

Author: ansjcy

release-notes/opensearch-query-insights.release-notes-2.16.0.0.md

@@ -0,0 +1,31 @@
+## Version 2.16.0.0 Release Notes
+Compatible with OpenSearch 2.16.0
+
+### Maintenance
+* Bootstrap query insights plugin repo with maintainers ([#2](https://github.com/opensearch-project/query-insights/pull/2))
+* Fix linux ci build failure when upgrade Actions runner to use node 20 ([#15](https://github.com/opensearch-project/query-insights/pull/15))
+* Move query categorization changes to plugin ([#16](https://github.com/opensearch-project/query-insights/pull/16))
+* Fix build error in NodeRequest class for 2.x ([#18](https://github.com/opensearch-project/query-insights/pull/18))
+* Fix query insights zip versioning ([#34](https://github.com/opensearch-project/query-insights/pull/34))
+* Fix integration test failures when running with security plugin ([#45](https://github.com/opensearch-project/query-insights/pull/45))
+
+### Bug Fixes
+* Validate lower bound for top n size ([#13](https://github.com/opensearch-project/query-insights/pull/13))
+* Fix stream serialization issues for complex data structures ([#13](https://github.com/opensearch-project/query-insights/pull/13))
+
+### Enhancements
+* Increment latency, cpu and memory histograms for multiple query types ([#30](https://github.com/opensearch-project/query-insights/pull/30))
+* Always populate resource usage metrics for categorization ([#41](https://github.com/opensearch-project/query-insights/pull/41))
+
+### Infrastructure
+* Configure Mend for query insights repo [#1](https://github.com/opensearch-project/query-insights/pull/1)
+* Set up gradle and CI for query insights [#4](https://github.com/opensearch-project/query-insights/pull/4)
+* Add build script to query insights plugin  [#14](https://github.com/opensearch-project/query-insights/pull/14)
+* Add backport GitHub actions [#17](https://github.com/opensearch-project/query-insights/pull/17)
+* Add maven publish workflow [#24](https://github.com/opensearch-project/query-insights/pull/24)
+* Add GitHub action for security enabled integration tests [#48](https://github.com/opensearch-project/query-insights/pull/48)
+* Add code hygiene checks for query insights  ([#51](https://github.com/opensearch-project/query-insights/pull/51))
+
+### Documentation
+* Update Readme file with user guide ([#5](https://github.com/opensearch-project/query-insights/pull/5))
+* Added 2.16 release notes ([#52](https://github.com/opensearch-project/query-insights/pull/52))