DOC: Update changelog

CHANGELOG.md

@@ -23,7 +23,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Property values specified by dicts do not have to contain a
   `collection_mode` key anymore. If none is given, the
-  `collection_mode` is determined from the `value`.
+  `collection_mode` is determined from the `value` as it is done for
+  values specified by strings:
+  - if `value` starts with '+', collection mode is "list".
+  - if `value` starts with '*', collection mode is "multiproperty".
+  - in all other cases, collection mode is "single".
 
 ### Deprecated ###