note editor in readme

Author: simonLeary42

README.md

@@ -24,7 +24,7 @@ Admin Features:
 - Automatic updating of LDAP to reflect current state of users, groups, organizations, PI groups
 - Cluster notices
   - Added to front page, mailed, and exposed via REST API
-- WYSIWYG HTML editor for webpage contents, cluster notices
+- WYSIWYG HTML editor ([ckeditor5](https://github.com/ckeditor/ckeditor5)) for webpage contents, cluster notices
 - Branding customization for multiple domains simultaneously
 - Custom UIDNumber / GIDNumber mappings for specific users
 - Login as another user