Updating configuration guide documentation
Updating configuration guide documentation

This change updates the content and grammar of the configuration
guide documentation.

Change-Id: I020c858828be7b09c072273b0401153c19074705

crobby/sahara,ekasitk/sahara,redhat-openstack/sahara,zhangjunli177/sahara,openstack/sahara,zhangjunli177/sahara,tellesnobrega/sahara,bigfootproject/sahara,redhat-openstack/sahara,bigfootproject/sahara,egafford/sahara,henaras/sahara,crobby/sahara,ekasitk/sahara,matips/iosr-2015,zhangjunli177/sahara,henaras/sahara,redhat-openstack/sahara,egafford/sahara,tellesnobrega/sahara,esikachev/sahara-backup,openstack/sahara,zhujzhuo/Sahara,ekasitk/sahara,zhujzhuo/Sahara,matips/iosr-2015,zhujzhuo/Sahara,henaras/sahara,matips/iosr-2015,esikachev/sahara-backup,esikachev/sahara-backup,crobby/sahara,bigfootproject/sahara