Update CHANGELOG.md

Author: gkjohnson

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project 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).
 
+## [0.3.4] - 2021-12-09
+### Added
+- Support for the "=" syntax as well as ":=" for macro parameters.
+
 ## [0.3.3] - 2021-08-05
 ### Fixed
 - Type definitions not working for Typescript users