[doc] add an example for cpu and memory hotplug
[doc] add an example for cpu and memory hotplug

As per #1271, i've added an example to document how to enable cpu and memory hotplug on a vm using govc.
bruceadowns/govmomi,bruceadowns/govmomi,bruceadowns/govmomi,vmware/govmomi,vmware/govmomi,vmware/govmomi