chore: Updating changelog

CHANGELOG.md

@@ -5,6 +5,14 @@ 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
+ - Added SubscribeEvent shim for delegate callbacks
+ - Extension method for reading JSON token as a GUID
+ - Added ToStringJsonConverter
+
+### Changed
+ - Significantly reduced size of JSON serialized Types
+ - Small logging optimizations
 
 ## [9.0.0] - 2019-01-29
 ### Added