Preparing CHANGELOG.md

Author: JonathanHUnity

com.unity.perception/CHANGELOG.md

@@ -5,19 +5,7 @@ All notable changes to this package will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
-## [Unreleased]
-
-### Added
-
-### Changed
-
-### Deprecated
-
-### Removed
-
-### Fixed
-
-## [0.4.0-preview.1] - 2020-08-07
+## [0.4.0-preview.1] - 2020-09-03
 
 ### Added