Ensure changelog file is standard format

Author: davidjgoss

CHANGELOG.md

@@ -2,11 +2,11 @@
 
 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/).
-
-Please see [CONTRIBUTING.md](./CONTRIBUTING.md) on how to contribute to Cucumber.
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 ### Added
-- Initial implementation
+- Initial release
+
+[Unreleased]: https://github.com/cucumber/cucumber-node/compare/2d5d66e...HEAD