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.

1991/rince/.entry.json

@@ -49,6 +49,14 @@
 	    "display_via_github" : true,
 	    "entry_text" : "original source code"
 	},
+	{
+	    "file_path" : "map-key.jpg",
+	    "inventory_order" : 60,
+	    "OK_to_edit" : false,
+	    "display_as" : "image",
+	    "display_via_github" : false,
+	    "entry_text" : "key to map image"
+	},
 	{
 	    "file_path" : "1991_rince.tar.bz2",
 	    "inventory_order" : 1415926535,

1991/rince/README.md

@@ -80,27 +80,12 @@ enjoyment high.
 
 ### Instructions:
 
-Key to map:
+**Key to map**:
+
+<img src="map-key.jpg"
+ alt="map to key"
+ width=800 height=400>
 
-```
-                            |
-     ######                 | | | /\   /--\  ==|    /\ | |  Directonal keys
-     ######  Solid Wall     | ----||    \/     /\   ||----  (unlock doors of
-     ######                 |     \/  ==|     \--/  \/       the same direction)
-                            |
-                            |   <<                    >>    Doors. Unlocked by
-             Blank space    |   <<   vvvvvv  ^^^^^^   >>    the above keys.
-                            |   <<                    >>
-                            |
-       ___                  | o__O\   O__O   ^__^   /O__o\
-      /   \  'Crushable'    | \___/  /----\ /----\  \___/  The four sprites for
-      \___/    boulder      |  _/_\  _/  \_ _/  \_  /_\_   your character :-)
-                            |
-       ___   uncrushable    |   /\   Diamonds. They can either be found lying
-      /@@@\    boulder      |  <  >  around (if only!) or manufacture by pushing
-      \@@@/                 |   \/   two 'crushable' rocks together.
-                            |
-```
 
 The general idea of the game is to collect all the diamonds. This must
 be done in the minimum amount of moves. I've allowed a margin of 5

1991/rince/index.html

@@ -441,24 +441,10 @@ it to see the rest of it .. :-) .) The general idea was to try and
 write the smallest playable game, but keep the playability and
 enjoyment high.</p>
 <h3 id="instructions">Instructions:</h3>
-<p>Key to map:</p>
-<pre><code>                            |
-     ######                 | | | /\   /--\  ==|    /\ | |  Directonal keys
-     ######  Solid Wall     | ----||    \/     /\   ||----  (unlock doors of
-     ######                 |     \/  ==|     \--/  \/       the same direction)
-                            |
-                            |   &lt;&lt;                    &gt;&gt;    Doors. Unlocked by
-             Blank space    |   &lt;&lt;   vvvvvv  ^^^^^^   &gt;&gt;    the above keys.
-                            |   &lt;&lt;                    &gt;&gt;
-                            |
-       ___                  | o__O\   O__O   ^__^   /O__o\
-      /   \  &#39;Crushable&#39;    | \___/  /----\ /----\  \___/  The four sprites for
-      \___/    boulder      |  _/_\  _/  \_ _/  \_  /_\_   your character :-)
-                            |
-       ___   uncrushable    |   /\   Diamonds. They can either be found lying
-      /@@@\    boulder      |  &lt;  &gt;  around (if only!) or manufacture by pushing
-      \@@@/                 |   \/   two &#39;crushable&#39; rocks together.
-                            |</code></pre>
+<p><strong>Key to map</strong>:</p>
+<p><img src="map-key.jpg"
+ alt="map to key"
+ width=800 height=400></p>
 <p>The general idea of the game is to collect all the diamonds. This must
 be done in the minimum amount of moves. I’ve allowed a margin of 5
 moves which brings the moves allowed to <code>484</code> (alter the value of <code>u</code> in
@@ -500,6 +486,7 @@ Take care that it’s facing in the correct direction.</p>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1991/rince/rince.alt2.c">rince.alt2.c</a> - second alternate source code</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1991/rince/rince.alt.c">rince.alt.c</a> - alternate source code</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1991/rince/rince.orig.c">rince.orig.c</a> - original source code</li>
+<li><a href="map-key.jpg">map-key.jpg</a> - key to map image</li>
 </ul>
 <h2 id="secondary-files">Secondary files</h2>
 <ul>