Updated CHANGELOG

Signed-off-by: Vincent Mrose <v.mrose@crefopay.de>

CHANGELOG.md

@@ -6,6 +6,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ## [Known issues]
 
 ## [Unreleased]
+- Error messages in the frontend no longer default to an empty string in some cases
+- Translations for all the translatable module strings were added
+- Help texts for the module configuration were added
+- Changed the initialization of the Javascript Library to always happen
+- Fixed issue #8
 
 ## [0.9.3] - 2019-04-04
 ### Fixed