Clarify README how Token is used and tracked by Article

[johnkary]

I'm having trouble figuring out how my domain object should implement the "token" concept. The current README shows Article->getToken() as a method, but it isn't clear to me from the documentation how that token is used by the workflow and its nodes.

Does Article->getToken() return a unique identifier for the Node the Article is currently at? Would it return a value like article.draft or article.deleted ?

If it is the current workflow state, in which example class would you set the token via Article->setToken($currentNodeToken)?

[trompette]

This is exactly the idea: the token value is the name of the node the instance is currently on.

The setToken() method should be called in every workflow event listener.