guest-migrate: add autostart command

Signed-off-by: Mark O Brien <markobri@redhat.com>

modules/sysadmin_guide/pages/guest_migrate.adoc

@@ -40,10 +40,16 @@ virsh dumpxml guestname > guest.xml
 depending on if the system was originally xen or such. I normally need
 to compare an existing xml on the target system and the one we dumped
 out to make up the differences.
-. Define the guest on the new machine: 'virsh define guest.xml'.
+. Define the guest on the new machine:
+
+....
+virsh define guest.xml
+....
+
 Depending on the changes in the xml this may not work and you will need
 to make many manual changes plus copy the guest.xml to
 `/etc/libvirtd/qemu` and do a `/sbin/service libvirtd restart`
+
 . Insert iptables rule for nc transfer:
 +
 ....
@@ -68,6 +74,13 @@ to it.
 ....
 ``virsh start guest``
 ....
+
+. To ensure that the new vm starts automatically after boot run:
+
+....
+virsh autostart guest
+....
+
 . On the source host, rename storage and undefine guest so it's not
 started.
 . In ansible change the host_vars to reflect the new host