Add CHANGELOG.md for release 0.2.0

Author: hipitihop

CHANGELOG.md

@@ -5,6 +5,6 @@ All notable changes to this project will be documented in this file.
 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]
+##  [0.2.0] - 2021-03-04
 ### Added
-- Merged PR #34 `::async-flow-fx/notify` NOP event handler for minimal flow signals. See ["Event Messaging" in README.md](https://github.com/day8/re-frame-async-flow-fx#event-messaging)
+- Merged PR #34 `::async-flow-fx/notify` NOP event handler for minimal flow signals. See ["Event Messaging" in README.md](https://github.com/day8/re-frame-async-flow-fx#event-messaging)