create a directory for infrastructure playbooks

Since we have a couple of infrastructure related playbooks
(additionnally to the roles we are using to deploy Ceph), it makes sense
to have them located in a separate directory.

Signed-off-by: Sébastien Han <seb@redhat.com>

infrastructure-playbooks/README.md

@@ -0,0 +1,5 @@
+Infrastructure playbooks
+========================
+
+This directory contains a variety of playbooks that can be used independently of the Ceph roles we have.
+They aim to perform infrastructure related tasks that would help use managing a Ceph cluster or performing certain operational tasks.