We have switched the docs to using the HTML5 doctype declaration in

  commit b1c81567
  Author: Daniel P. Berrange <berrange@redhat.com>
  Date:   Wed Jul 26 18:01:25 2017 +0100

    docs: switch to using HTML5 doctype declaration
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>