update changelog

Author: robkooper

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](http://keepachangelog.com/) 
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## Unreleased
+
+### Added
+- Simple extractors now support datasets, can also create new datasets.
+
 ## 2.2.3 - 2019-10-14
 
 ### Fixed