Add changelog

Signed-off-by: Vinay Krishna Pudyodu <[email protected]>

Author: vinaykpud

CHANGELOG.md

@@ -6,7 +6,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ## [Unreleased 2.x]
 ### Added
 - Renaming the node role search to warm ([#17573](https://github.com/opensearch-project/OpenSearch/pull/17573))
-- Introduce a new search node role ([]())
+- Introduce a new search node role ([#17620](https://github.com/opensearch-project/OpenSearch/pull/17620))
 
 ### Dependencies
 - Bump `ch.qos.logback:logback-core` from 1.5.16 to 1.5.17 ([#17609](https://github.com/opensearch-project/OpenSearch/pull/17609))