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.

1984/decot/index.html

@@ -141,7 +141,7 @@ Location: <a href="../../location.html#US">US</a> - <em>United States of America
 <!-- 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> all</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    make all</code></pre>
 <p>NOTE: there is an <a href="#alternate-code">alternate version</a> which will only work if
 you have an old enough compiler or a compiler that supports <code>-traditional-cpp</code>.
 The original code was fixed in 2023 to not require this.</p>
@@ -150,15 +150,15 @@ The original code was fixed in 2023 to not require this.</p>
 <pre><code>    STATUS: INABIAF - please **DO NOT** fix</code></pre>
 <p>For more detailed information see <a href="../../bugs.html#1984_decot">1984 decot bugs</a>.</p>
 <h2 id="to-use">To use:</h2>
-<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">./decot</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./decot</code></pre>
 <h2 id="alternate-code">Alternate code:</h2>
 <p>This alternate code, the original, requires a compiler that supports
 <code>-traditional-cpp</code> or an old enough compiler. If you have such a compiler you
 can use this version.</p>
 <h3 id="alternate-build">Alternate build:</h3>
-<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="fu">make</span> alt</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    make alt</code></pre>
 <h3 id="alternate-use">Alternate use:</h3>
-<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="ex">./decot.alt</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./decot.alt</code></pre>
 <h2 id="judges-remarks">Judges’ remarks:</h2>
 <p>This program prints out what looks like a fragment of C code.</p>
 <p>Is this a <strong>bug</strong> or is this a <strong>feature</strong>? To help choose
@@ -166,13 +166,13 @@ the judges offer this one comment: understand remarks!</p>
 <h3 id="historical-remarks">Historical remarks:</h3>
 <p>Some new (in 1984) compilers disliked line 15 of the original source, so we
 changed it from:</p>
-<div class="sourceCode" id="cb6"><pre class="sourceCode c"><code class="sourceCode c"><span id="cb6-1"><a href="#cb6-1" aria-hidden="true" tabindex="-1"></a>    <span class="cf">for</span><span class="op">(</span>signal<span class="op">=</span><span class="dv">0</span><span class="op">;*</span>k <span class="op">*</span> x <span class="op">*</span> __FILE__ <span class="op">*</span>i<span class="op">;)</span> <span class="cf">do</span> <span class="op">{</span></span></code></pre></div>
+<pre class="&lt;!---c--&gt;"><code>    for(signal=0;*k * x * __FILE__ *i;) do {</code></pre>
 <p>to:</p>
-<div class="sourceCode" id="cb7"><pre class="sourceCode c"><code class="sourceCode c"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a>    <span class="cf">for</span><span class="op">(</span>signal<span class="op">=</span><span class="dv">0</span><span class="op">;*</span>k <span class="op">*</span>x <span class="op">*</span> __FILE__ <span class="op">*</span>i<span class="op">;)</span> <span class="cf">do</span> <span class="op">{</span></span></code></pre></div>
+<pre class="&lt;!---c--&gt;"><code>    for(signal=0;*k *x * __FILE__ *i;) do {</code></pre>
 <p>To see what we mean look at the <a href="decot.orig.c">original source file</a>. The
 <a href="decot.alt.c">alternate code</a> is the version that has this modification. The
 fixed version has instead:</p>
-<div class="sourceCode" id="cb8"><pre class="sourceCode c"><code class="sourceCode c"><span id="cb8-1"><a href="#cb8-1" aria-hidden="true" tabindex="-1"></a>    <span class="cf">for</span><span class="op">(</span>signal<span class="op">=</span><span class="dv">0</span><span class="op">;*</span>k <span class="op">*=</span> <span class="op">*</span> __FILE__ <span class="op">*</span>i<span class="op">;)</span> <span class="cf">do</span> <span class="op">{</span></span></code></pre></div>
+<pre class="&lt;!---c--&gt;"><code>    for(signal=0;*k *= * __FILE__ *i;) do {</code></pre>
 <h2 id="authors-remarks">Author’s remarks:</h2>
 <p>No remarks were provided by the author.</p>
 <!--