Changelog update

Signed-off-by: Maxim Molchanov <[email protected]>

Author: Maksym Molchanov

CHANGELOG.md

@@ -5,6 +5,8 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 ## [Unreleased]
 ### Dependencies
 ### Added
+- Adds `InnerHits` field to `SearchResp` ([#672](https://github.com/opensearch-project/opensearch-go/pull/672))
+
 ### Changed
 ### Deprecated
 ### Removed