add changelog

Author: nadar

core/CHANGELOG.md

@@ -3,8 +3,9 @@
 All notable changes to this project will be documented in this file. This project adheres to [Semantic Versioning](http://semver.org/).
 In order to read more about upgrading and BC breaks have a look at the [UPGRADE Document](UPGRADE.md).
 
-## 2.1.0
+## 2.1.0 (27. April 2022)
 
++ [#2123](https://github.com/luyadev/luya/pull/2123) Added new property `$events` to add custom events in `luya\behaviors\JsonBehavior`. F.e `['class' => JsonBehavior::class, 'events' => [NgRestModel::EVENT_AFTER_NGREST_FIND => 'decodeAttributes']]`.
 + [#2118](https://github.com/luyadev/luya/pull/2118) Removed conflicting `$attributeLabels` property from DynamicModel (Yii provides this option since 2.0.35, therefore not required by LUYA anymore).
 
 ## 2.0.2 (7. December 2021)