doc: Fixed a minor typo in the document
doc: Fixed a minor typo in the document

In the Demo part of the Document, for both Vagrant and Bare metal the description was mentioned as "Deployment from scratch on bare metal machines".
Changed "bare metal" to "vagrant" for Vagrant section

Signed-off-by: Nizamudeen <5ad140d5f4b7cad9d45ac9c0d051724ab2960e88@redhat.com>

ceph/ceph-ansible,ceph/ceph-ansible