Format change log

Signed-off-by: Binlong Gao <[email protected]>

Author: gaobinlong

CHANGELOG.md

@@ -16,8 +16,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Add overload constructor for Translog to accept Channel Factory as a parameter ([#18918](https://github.com/opensearch-project/OpenSearch/pull/18918))
 - Add subdirectory-aware store module with recovery support ([#19132](https://github.com/opensearch-project/OpenSearch/pull/19132))
 - Field collapsing supports search_after ([#19261](https://github.com/opensearch-project/OpenSearch/pull/19261))
-
 - Add a dynamic cluster setting to control the enablement of the merged segment warmer ([#18929](https://github.com/opensearch-project/OpenSearch/pull/18929))
+
 ### Changed
 - Add CompletionStage variants to methods in the Client Interface and default to ActionListener impl ([#18998](https://github.com/opensearch-project/OpenSearch/pull/18998))
 - IllegalArgumentException when scroll ID references a node not found in Cluster ([#19031](https://github.com/opensearch-project/OpenSearch/pull/19031))