update CHANGELOG for 0.3.0 release

Author: shieldo

CHANGELOG.md

@@ -4,6 +4,11 @@ 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).
 
+## [0.3.0] - 2021-02-24
+
+### Changed
+- using Parsica release 0.7, with new `Parsica` PHP namespace and new package name (`parsica-php/parsica`)
+
 ## [0.2.0] - 2021-01-13
 
 ### Added