[DOC] note for 9.0+ users

im_notif/README.rst

@@ -6,3 +6,8 @@ Description: https://apps.odoo.com/apps/modules/8.0/im_notif/
 Further information and discussion: https://yelizariev.github.io/odoo/module/2015/02/18/im-notifications.html
 
 Tested on Odoo 8.0 ab7b5d7732a7c222a0aea45bd173742acd47242d
+
+Odoo 9.0+
+=========
+
+For newer version the module is not needed, cause there is similar built-in feature