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.

2012/deckmyn/deckmyn.html

@@ -124,7 +124,7 @@
 
 <h1 id="user-manual">USER MANUAL</h1>
 <h2 id="calling-the-program">Calling the program</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="ex">./deckmyn</span> <span class="st">&quot;</span><span class="kw">`</span><span class="fu">cat</span> deckmyn.c<span class="kw">`</span><span class="st">&quot;</span> <span class="st">&quot;</span><span class="kw">`</span><span class="fu">cat</span> musicfile<span class="kw">`</span><span class="st">&quot;</span> <span class="op">&gt;</span> output.pbm</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./deckmyn &quot;`cat deckmyn.c`&quot; &quot;`cat musicfile`&quot; &gt; output.pbm</code></pre>
 <p>Then display <code>output.pbm</code>.</p>
 <p>This minimalistic music notator expects two command line arguments. The first is
 the font description embedded in the source code. Notice that you don’t pass the
@@ -186,7 +186,7 @@ clef. <code>"K"</code> followed by any other letter will just default to a stand
 </ol>
 <h2 id="examples">Examples</h2>
 <p>Blank music paper (with G clef):</p>
-<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">./deckmyn</span> <span class="st">&quot;</span><span class="kw">`</span><span class="fu">cat</span> deckmyn.c<span class="kw">`</span><span class="st">&quot;</span> <span class="st">&quot;sz sa x  s1 x  s1 x  s1 x  s1 x  s1 &quot;</span><span class="op">&gt;</span> blank.pbm</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./deckmyn &quot;`cat deckmyn.c`&quot; &quot;sz sa x  s1 x  s1 x  s1 x  s1 x  s1 &quot;&gt; blank.pbm</code></pre>
 <p>With an F clef:</p>
 <pre><code>    ./deckmyn &quot;`cat deckmyn.c`&quot; &quot;KF sz sa x  s1 x  s1 x  s1 x  s1 x  s1 &quot;&gt; blank.pbm</code></pre>
 <p>Notice how only the first staff (or any staff) needs to have the full length.</p>