Rework the WildFly and WildFly Preview doc to reflect EE > 8 is no longer a difference

https://docs.wildfly.org/26/WildFly_and_WildFly_Preview.html needs a refresh.

What it should say for WF 27 depends on what we decide to do with WFP for that release; e.g do we go back to not having the embedded-broker by default, do we leave the deployment transformation ability etc.