DOC: added Changelog

CHANGELOG.md

@@ -11,7 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - New class to collect possible problems whith the data model
 
 ### Changed ###
-
+- The WebUIHandler is now a python logging formatter.
 - instead of `get_entity`, type-specific functions are used in
   `cfood.py` when the type of the entity in question is known.
 - Logger is used instead of `print` for errors in `crawler.py`.