Add 2.16 release note (#817)

Signed-off-by: Jackie Han <jkhanjob@gmail.com>

Author: jackiehanyang

release-notes/opensearch-anomaly-detection-dashboards.release-notes-2.16.0.0.md

@@ -0,0 +1,15 @@
+## Version 2.16.0.0 Release Notes
+
+Compatible with OpenSearch Dashboards 2.16.0
+
+### Features
+* allow date_nanos dates in timestamp selection ([#795](https://github.com/opensearch-project/anomaly-detection-dashboards-plugin/pull/795))
+* MDS version decoupling ([#806](https://github.com/opensearch-project/anomaly-detection-dashboards-plugin/pull/806))
+* AD side navigation redesign ([#810](https://github.com/opensearch-project/anomaly-detection-dashboards-plugin/pull/810))
+
+### Infrastructure
+* Update Frontend CI to use JDK21 ([#798](https://github.com/opensearch-project/anomaly-detection-dashboards-plugin/pull/798))
+
+### Maintenance
+
+* Update 2.x to 2.16.0 ([#769](https://github.com/opensearch-project/anomaly-detection-dashboards-plugin/pull/808))