Add changelog

Signed-off-by: Vinay Krishna Pudyodu <vinkrish.neo@gmail.com>

Author: vinaykpud

CHANGELOG.md

@@ -28,6 +28,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Pass index settings to system ingest processor factories. ([#18708](https://github.com/opensearch-project/OpenSearch/pull/18708))
 - Include named queries from rescore contexts in matched_queries array ([#18697](https://github.com/opensearch-project/OpenSearch/pull/18697))
 - Add the configurable limit on rule cardinality ([#18663](https://github.com/opensearch-project/OpenSearch/pull/18663))
+- Optimization in Numeric Terms Aggregation query for Large Bucket Counts([#18702](https://github.com/opensearch-project/OpenSearch/pull/18702))
 
 ### Changed
 - Update Subject interface to use CheckedRunnable ([#18570](https://github.com/opensearch-project/OpenSearch/issues/18570))