doc: add release notes for 2.9.0 (opensearch-project#232)

Signed-off-by: Lin Wang <[email protected]>

release-notes/opensearch-ml-commons-dashboards.release-notes-2.9.0.0.md

@@ -0,0 +1,22 @@
+## Version 2.9.0.0 Release Notes
+
+Compatible with OpenSearch 2.9.0
+
+
+### Features
+
+* Exclude remote models in admin UI overview page. ([#225](https://github.com/opensearch-project/ml-commons-dashboards/pull/225)) 
+* Remove experiment banner and enable plugin by default. ([#229](https://github.com/opensearch-project/ml-commons-dashboards/pull/229))
+
+
+
+### Enhancements
+
+
+* Open external link in new blank page. ([#211](https://github.com/opensearch-project/ml-commons-dashboards/pull/211))
+
+
+### Bug Fixes
+
+* Remove refresh interval background in dark mode. ([#209](https://github.com/opensearch-project/ml-commons-dashboards/pull/209))
+* Update to correct machine learning document address for experiment banner and empty screen. ([#210](https://github.com/opensearch-project/ml-commons-dashboards/pull/210))