Added documentaiton section to README.md to point to gitbooks guide.
Added documentaiton section to README.md to point to gitbooks guide.

lance/wildfly-swarm,lance/wildfly-swarm,lance/wildfly-swarm,heiko-braun/wildfly-swarm,twilking/wildfly-swarm,heiko-braun/wildfly-swarm,heiko-braun/wildfly-swarm,twilking/wildfly-swarm,twilking/wildfly-swarm,heiko-braun/wildfly-swarm,lance/wildfly-swarm,heiko-braun/wildfly-swarm,twilking/wildfly-swarm,twilking/wildfly-swarm