Adde changelog

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

Author: vinaykpud

CHANGELOG.md

@@ -11,6 +11,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Add Setting to adjust the primary constraint weights ([#16471](https://github.com/opensearch-project/OpenSearch/pull/16471))
 - Switch from `buildSrc/version.properties` to Gradle version catalog (`gradle/libs.versions.toml`) to enable dependabot to perform automated upgrades on common libs ([#16284](https://github.com/opensearch-project/OpenSearch/pull/16284))
 - Add dynamic setting allowing size > 0 requests to be cached in the request cache ([#16483](https://github.com/opensearch-project/OpenSearch/pull/16483/files))
+- Added implementation for the stats calculation for search and regular replica in shards ([#16677](https://github.com/opensearch-project/OpenSearch/pull/16677))
 
 ### Dependencies
 - Bump `com.azure:azure-storage-common` from 12.25.1 to 12.27.1 ([#16521](https://github.com/opensearch-project/OpenSearch/pull/16521))