Adds CHANGELOG entry for #22

Author: michalbundyra

CHANGELOG.md

@@ -8,6 +8,12 @@ All notable changes to this project will be documented in this file, in reverse
 
 - [#24](https://github.com/zendframework/zend-mvc-plugin-flashmessenger/pull/24) adds support for PHP 7.3.
 
+- [#22](https://github.com/zendframework/zend-mvc-plugin-flashmessenger/pull/22) adds `Zend\Mvc\Plugin\FlashMessenger\View\HelperTrait`,
+  which can be used to provide IDE autocompletion for view helpers
+  provided by zend-mvc-plugin-flashmessenger. See
+  https://docs.zendframework.com/zend-mvc-plugin-flashmessenger/flash-messenger-view-helper/#ide-auto-completion-in-templates
+  for more information.
+
 ### Changed
 
 - Nothing.