Docu - Create a new Add-on / WidgetSet

I want ot create a new Add-on with vaadin 7 with: 
Clientside (with gwt)
Serverside
Connector

I have found a documentation for vaadin 6 in 
https://vaadin.com/book/vaadin6/-/page/gwt.widgetset.html

Is there also a documentation for vaadin 7?
Where can i get some infos for it?

The Vaadin 7 docs are located at https://vaadin.com/docs

Inside Vaadin Framework you will find also sections related to client side widgets and client-server integration