v2v: use programlisting instead of screen

Signed-off-by: May <sirhuntthepure@users.noreply.github.com>
admin/hosts: fix minor error

Signed-off-by: May <sirhuntthepure@users.noreply.github.com>
admin/vdsm-and-hooks: appendix B done

Signed-off-by: May <sirhuntthepure@users.noreply.github.com>