Adding to CHANGELOG

Author: ckittl

CHANGELOG.md

@@ -5,6 +5,8 @@ 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]
+### Changed
+- Actor-based implementation for better concurrency
 
 ## [1.0.0] - 2021-08-03
 ### Added