Add changelog

Signed-off-by: Rishab Nahata <rnnahata@amazon.com>

Author: imRishN

CHANGELOG.md

@@ -10,6 +10,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Added release notes for 2.2.1 ([#4344](https://github.com/opensearch-project/OpenSearch/pull/4344))
 - Label configuration for dependabot PRs ([#4348](https://github.com/opensearch-project/OpenSearch/pull/4348))
 - Support for HTTP/2 (server-side) ([#3847](https://github.com/opensearch-project/OpenSearch/pull/3847))
+- Add APIs (GET/PUT) to decommission awareness attribute ([#4261](https://github.com/opensearch-project/OpenSearch/pull/4261))
 
 ### Changed
 - Dependency updates (httpcore, mockito, slf4j, httpasyncclient, commons-codec) ([#4308](https://github.com/opensearch-project/OpenSearch/pull/4308))
@@ -29,7 +30,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Add timeout on Mockito.verify to reduce flakyness in testReplicationOnDone test([#4314](https://github.com/opensearch-project/OpenSearch/pull/4314))
 - Commit workflow for dependabot changelog helper ([#4331](https://github.com/opensearch-project/OpenSearch/pull/4331))
 - Fixed cancellation of segment replication events ([#4225](https://github.com/opensearch-project/OpenSearch/pull/4225))
-- Bugs for dependabot changelog verifier workflow ([#4364](https://github.com/opensearch-project/OpenSearch/pull/4364)) 
+- Bugs for dependabot changelog verifier workflow ([#4364](https://github.com/opensearch-project/OpenSearch/pull/4364))
 
 ### Security
 - CVE-2022-25857 org.yaml:snakeyaml DOS vulnerability ([#4341](https://github.com/opensearch-project/OpenSearch/pull/4341))