Added unreleased section to changelog

Author: loiswells97

CHANGELOG.md

@@ -3,6 +3,8 @@ 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]
+
 ## [0.4.0]
 
 ### Added