add release note 2.9.0

Signed-off-by: Mingshi Liu <[email protected]>

release-notes/search-processor.release-notes-2.9.0.md

@@ -0,0 +1,9 @@
+## Version 2.9.0.0 Release Notes
+
+Compatible with OpenSearch 2.9.0
+
+
+### Enhancements
+* Support contextual metadata to use when getting personalized reranking ([#144](https://github.com/opensearch-project/search-processor/pull/144))
+* Scoring logic for reranking open search hits based on personalize campaign response ([#147](https://github.com/opensearch-project/search-processor/pull/147))
+* Add ignoreFailure and pipelineContext ([#152](https://github.com/opensearch-project/search-processor/pull/152))