Update changelog

Signed-off-by: Songkan Tang <[email protected]>

CHANGELOG.md

@@ -21,6 +21,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Support prefix list for remote repository attributes([#16271](https://github.com/opensearch-project/OpenSearch/pull/16271))
 - Add new configuration setting `synonym_analyzer`, to the `synonym` and `synonym_graph` filters, enabling the specification of a custom analyzer for reading the synonym file ([#16488](https://github.com/opensearch-project/OpenSearch/pull/16488)).
 - Add stats for remote publication failure and move download failure stats to remote methods([#16682](https://github.com/opensearch-project/OpenSearch/pull/16682/))
+- Introduce log pattern lib with initial implementation of Brain algorithm log parser([#16751](https://github.com/opensearch-project/OpenSearch/pull/16751))
 
 ### Dependencies
 - Bump `com.google.cloud:google-cloud-core-http` from 2.23.0 to 2.47.0 ([#16504](https://github.com/opensearch-project/OpenSearch/pull/16504))