Added a tutorial

Mac/Demo/index.html

@@ -9,6 +9,10 @@ already familiar with Python and, to some extent, with MacOS Toolbox
 programming. Other readers may find something interesting here too,
 your mileage may vary. <p>
 
+There is a companion document <a href="using.html">Using Python on the Mac</a>
+which you should read before starting here: it explains the basics of using
+python on the Macintosh. <p>
+
 Another set of Macintosh-savvy examples, more aimed at beginners, is
 maintained by Joseph Strout, at <A
 HREF="http://www-acs.ucsd.edu/~jstrout/python/">
@@ -91,4 +95,4 @@ documentation. <p>
 
 <HR>
 <A HREF="http://www.cwi.nl/~jack">Jack Jansen</A>,
-<A HREF="mailto:jack@cwi.nl">jack@cwi.nl</A>, 6-Mar-1996.
+<A HREF="mailto:jack@cwi.nl">jack@cwi.nl</A>, 7-Apr-1996.