README: Reference some more comprehensive docs from the Quick-start

The quick-start is not terribly comprehensive for beginners.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jan Beulich <JBeulich@suse.com>

README

@@ -26,7 +26,12 @@ http://wiki.xen.org/
 Quick-Start Guide
 =================
 
-First, there are a number of prerequisites for building a Xen source
+First, this is just a quick-start guide. For more comprehensive
+information see the INSTALL file and the Xen wiki at
+http://wiki.xenproject.org and in particular
+http://wiki.xenproject.org/wiki/Getting_Started.
+
+Second, there are a number of prerequisites for building a Xen source
 release. Make sure you have all the following installed, either by
 visiting the project webpage or installing a pre-built package
 provided by your OS distributor: