Add changelog entry

Author: XedinUnknown

CHANGELOG.md

@@ -5,5 +5,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [[*next-version*]] - YYYY-MM-DD
+
+## [0.1.0-alpha1] - 2023-08-18
 ### Added
 - `Client` implementation, with tests (#1).