Reference PR's in changelog

Author: gurki

CHANGELOG.md

@@ -3,10 +3,14 @@ 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]
+## [v2.2.0] - 2019-09-10
 
 ### Added
-- Add Google Turbo colormap preset
+- Add Google Turbo colormap preset [\#6](https://github.com/gurki/vivid/pull/6)
+
+
+### Fixed
+- Use correct standard library math functions, add missing header includes [\#5](https://github.com/gurki/vivid/pull/5)
 
 
 ## [v2.1.0] - 2019-06-04