Add changelog

Signed-off-by: Asim Mahmood <asim.seng@gmail.com>

Author: asimmahmood1

CHANGELOG.md

@@ -29,6 +29,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Add all-active ingestion as docrep equivalent in pull-based ingestion ([#19316](https://github.com/opensearch-project/OpenSearch/pull/19316))
 - Adding logic for histogram aggregation using skiplist ([#19130](https://github.com/opensearch-project/OpenSearch/pull/19130))
 - Add skip_list param for date, scaled float and token count fields ([#19142](https://github.com/opensearch-project/OpenSearch/pull/19142))
+- Enable skip_list for @timestamp field or index sort field by default([#19480](https://github.com/opensearch-project/OpenSearch/pull/19480))
 - Implement GRPC MatchPhrase, MultiMatch queries ([#19449](https://github.com/opensearch-project/OpenSearch/pull/19449))
 - Optimize gRPC transport thread management for improved throughput ([#19278](https://github.com/opensearch-project/OpenSearch/pull/19278))
 - Implement GRPC Boolean query and inject registry for all internal query converters ([#19391](https://github.com/opensearch-project/OpenSearch/pull/19391))