The text you see while editing a page comes out of this file:
inc/lang/<LANGUAGE>/edit.txt
(Replace <LANGUAGE> with the one you setup in DW config, mybe "en" in your case?)
Here you find the source
Edit the page and hit ''Save''. See [[wiki:syntax]] for Wiki syntax. Please edit the page only if you can **improve** it. If you want to test some things, learn to make your first steps on the [[playground:playground|playground]].
and you could replace the link for "wiki:syntax".
But i won't recommend this because it may be overwritten at the next update. Also you should consider if it is a good plan to move the syntax-page inside playground. Playground, normally is writeable by any user. So any user could change the upper part in the edit mode.