add hack-a-round for language specified markdown code blocks

When language is specified in a markdown code block such as:

````
```c
    printf("Hello, world!\n");
```
````

is used, the resulting HTML as produced by `pandoc(1)` combined
with our revised `ioccc.css` is not intent the code block well.

A temporary "_hack-a-round_" is to turn the "markdown code language
specifier" into an HTML comment.  For example:

````
```<!---c-->
    printf("Hello, world!\n");
```
````

This commits turns off existing markdown code language specifiers
for now, while preserving our ability to restore them in the future
when a better  "_hack-a-round_" to the "markdown code language
specifier" problem is found.

The HTML impact if this "_hack-a-round_" is to produce HTML that
looks like this:

```
<pre class="&lt;!---c--&gt;"><code> .. </code></pre>
```

We might be able to create a complex set of classes for each markdown
code language (there won't be very many) in `ioccc.css`, or we might
find a more general CSS (or maybe `pandoc(1)`?) solution.

For now, this hack-a-round will have to do.

2004/gavare/index.html

@@ -141,18 +141,18 @@ Location: <a href="../../location.html#SE">SE</a> - <em>Kingdom of Sweden</em> (
 <!-- START: this line starts content for HTML phase 21 by: bin/pandoc-wrapper.sh via bin/md2html.sh -->
 
 <h2 id="to-build">To build:</h2>
-<div class="sourceCode" id="cb1"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a>    <span class="fu">make</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    make</code></pre>
 <p>There are three alternate versions; see <a href="#alternate-code">alternate code</a> below
 for more details.</p>
 <h2 id="to-use">To use:</h2>
-<div class="sourceCode" id="cb2"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" aria-hidden="true" tabindex="-1"></a>    <span class="ex">./gavare</span> <span class="op">&gt;</span> ioccc_ray.ppm</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./gavare &gt; ioccc_ray.ppm</code></pre>
 <p>Open <code>ioccc_ray.ppm</code> with a viewer capable of viewing PPM files. Alternatively,
 if you have ImageMagick installed, you can convert it to a jpeg:</p>
-<div class="sourceCode" id="cb3"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a>    <span class="ex">convert</span> ioccc_ray.ppm ioccc_ray.jpg</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    convert ioccc_ray.ppm ioccc_ray.jpg</code></pre>
 <p>and then view <code>ioccc_ray.jpg</code> in a graphics viewer, editor or web browser.</p>
 <h2 id="try">Try:</h2>
 <p>If you have <code>xv(1)</code> you can do:</p>
-<div class="sourceCode" id="cb4"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb4-1"><a href="#cb4-1" aria-hidden="true" tabindex="-1"></a>    <span class="ex">./gavare</span> <span class="kw">|</span> <span class="ex">xv</span> <span class="at">-</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./gavare | xv -</code></pre>
 <p>to not worry about writing it to a file and just viewing the image it creates.</p>
 <h2 id="alternate-code">Alternate code:</h2>
 <p>The alt code <a href="gavare.alt.c">gavare.alt.c</a> allows you to change the size of the
@@ -165,18 +165,18 @@ was used during development, which we have included in the file
 on <code>stdout</code> which theoretically should work in Windows.</p>
 <h3 id="alternate-build">Alternate build:</h3>
 <p>To build the configurable and unobfuscated versions:</p>
-<div class="sourceCode" id="cb5"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a>    <span class="fu">make</span> alt</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    make alt</code></pre>
 <p>To change the default size from 1024x768 try:</p>
-<div class="sourceCode" id="cb6"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb6-1"><a href="#cb6-1" aria-hidden="true" tabindex="-1"></a>    <span class="fu">make</span> clobber XX=640 YY=480 alt</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    make clobber XX=640 YY=480 alt</code></pre>
 <p>You might also wish to change the anti-alias setting:</p>
-<div class="sourceCode" id="cb7"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a>    <span class="fu">make</span> clobber AA=2 alt</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    make clobber AA=2 alt</code></pre>
 <p>You may of course combine the above two commands and give any combination you
 wish.</p>
 <p>This is not possible with the author’s version but it is with the alt versions
 (Windows - see below - and otherwise).</p>
 <p>As the Windows version will not compile on most viewers’ systems we do not build
 it with <code>make alt</code>; instead try:</p>
-<div class="sourceCode" id="cb8"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" aria-hidden="true" tabindex="-1"></a>    <span class="fu">make</span> alt2</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    make alt2</code></pre>
 <h3 id="alternate-use">Alternate use:</h3>
 <p>Use <code>gavare.alt</code>, <code>gavare.r3</code> or <code>gavare.alt2</code> as you would <code>gavare</code> above.</p>
 <h2 id="judges-remarks">Judges’ remarks:</h2>