Fix code blocks in 1991 and part of 1992

In 1991 the code blocks in the html files should look better with
smaller screens.  In one entry, rince, an image was added as the
formatting is too complicated to get right. The text was changed from
two columns to one column and then a screenshot was taken so that it's a
bit easier to see with smaller widths. This looks fairly good on mobile
phones too. The only downside, of course, is if the web pages ever
change to have a different background or code colour it won't match but
it did not look right with mobile phones. This required a manifest
update.

In 1992 one entry's html file defeated me for now so I had to stop. This
can be looked at later. The last entry I am committing changes to is
1991/buzzard.1. It was buzzard.2/buzzard.2.design.md that is a big
problem and will have to be done another time.

thanks-for-help.html

@@ -1579,6 +1579,9 @@ added a newline at the end of the screen to be more user friendly.</p>
 remove the maximum number of moves you may make and another to let you configure
 the maximum number of moves, even if that is making it harder to win. Naturally
 the above fix was applied to these versions too.</p>
+<p>The file <code>map-key.jpg</code> was added to help those with smaller screens as
+unfortunately the formatting of the key to the map was not easy to change in a
+way without ruining how it looks (beyond making it one column only).</p>
 <div id="1991_westley">
 <h2 id="winning-entry-1991westley">Winning entry: <a href="1991/westley/index.html">1991/westley</a></h2>
 <h3 id="winning-entry-source-code-westley.c-4">Winning entry source code: <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1991/westley/westley.c">westley.c</a></h3>