PING PeterS: Draw Guide 3.5 Preface edited

[jeanweber]

Peter, I've added a bit to the end of your draft Preface, to make it
more consistent with the other books. See what you think.

http://www.odfauthors.org/libreoffice/english/draw-guide/feedback-lo3.5/dg3.5-preface/view

--Jean