add change log

Signed-off-by: panguixin <[email protected]>

Author: bugmakerrrrrr

CHANGELOG.md

@@ -111,6 +111,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - [Streaming Indexing] Introduce new experimental server HTTP transport based on Netty 4 and Project Reactor (Reactor Netty) ([#9672](https://github.com/opensearch-project/OpenSearch/pull/9672))
 - Add template snippets support for field and target_field in KV ingest processor ([#10040](https://github.com/opensearch-project/OpenSearch/pull/10040))
 - Allowing pipeline processors to access index mapping info by passing ingest service ref as part of the processor factory parameters ([#10307](https://github.com/opensearch-project/OpenSearch/pull/10307))
+- Allow changing number of replicas of searchable snapshot index ([#11317](https://github.com/opensearch-project/OpenSearch/pull/11317))
 
 ### Dependencies
 - Bump `com.google.api.grpc:proto-google-common-protos` from 2.10.0 to 2.25.1 ([#10208](https://github.com/opensearch-project/OpenSearch/pull/10208), [#10298](https://github.com/opensearch-project/OpenSearch/pull/10298))