chore: Update changelog for release 0.3.0

Author: richtea

CHANGELOG.md

@@ -5,7 +5,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
-## Unreleased
+## [0.3.0] - 2022-03-25
 
 ### Added
 
@@ -79,6 +79,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - Initial version
 
+[0.3.0]: https://github.com/release-flow/keep-a-changelog-action-example/compare/v0.2.2...v0.3.0
+
 [0.2.2]: https://github.com/release-flow/keep-a-changelog-action-example/compare/v0.2.1...v0.2.2
 
 [0.2.1]: https://github.com/release-flow/keep-a-changelog-action-example/compare/v0.2.0...v0.2.1