Document correct number of baremetal nodes
Document correct number of baremetal nodes

This was changed from 4 to 2 in
Iaa79c9ff1573edf7619825bba530c80623769a3a

Change-Id: I806c86e9c46af448ad254c7ed0a46dc06340bdf6

eprasad/instack-undercloud,rdo-management/instack-undercloud,bcrochet/instack-undercloud,rdo-management/instack-undercloud,dpkshetty/instack-undercloud,bcrochet/instack-undercloud,dpkshetty/instack-undercloud,dmsimard/instack-undercloud,dmsimard/instack-undercloud,eprasad/instack-undercloud