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.

2001/anonymous/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```sh
+```<!---sh-->
     make
 ```
 
@@ -27,14 +27,14 @@ For more detailed information see [2001 anonymous bugs](../../bugs.html#2001_ano
 
 ## To use:
 
-```sh
+```<!---sh-->
     ./anonymous x86_program
 ```
 
 
 ## Try:
 
-```sh
+```<!---sh-->
     ./try.sh
 
     ./anonymous anonymous.bed # if able to compile as a 32-bit (-m32) ELF binary
@@ -64,14 +64,14 @@ that :-(
 
 ### Alternate build:
 
-```sh
+```<!---sh-->
     make alt
 ```
 
 
 ### Alternate use:
 
-```sh
+```<!---sh-->
     ./anonymous.ten.alt
 
     ./anonymous.bed.alt

2001/anonymous/index.html

@@ -141,7 +141,7 @@ Location: <a href="../../location.html#GB">GB</a> - <em>United Kingdom of Great
 <!-- 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>The programs that this program is supposed to act on,
 <a href="anonymous.ten.c">anonymous.ten.c</a> and <a href="anonymous.bed.c">anonymous.bed.c</a>,
 compiled with <code>make</code>, MUST be compiled as 32-bit ELF binaries. In the case that
@@ -155,11 +155,11 @@ whatever your system will compile them as).</p>
 <pre><code>    STATUS: INABIAF - please **DO NOT** fix</code></pre>
 <p>For more detailed information see <a href="../../bugs.html#2001_anonymous">2001 anonymous 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">./anonymous</span> x86_program</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./anonymous x86_program</code></pre>
 <h2 id="try">Try:</h2>
-<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">./try.sh</span></span>
-<span id="cb4-2"><a href="#cb4-2" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb4-3"><a href="#cb4-3" aria-hidden="true" tabindex="-1"></a>    <span class="ex">./anonymous</span> anonymous.bed <span class="co"># if able to compile as a 32-bit (-m32) ELF binary</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./try.sh
+
+    ./anonymous anonymous.bed # if able to compile as a 32-bit (-m32) ELF binary</code></pre>
 <p>NOTE: if the 32-bit version cannot be compiled the script will at least compile
 <a href="anonymous.ten.c">anonymous.ten</a> as a 64-bit program (or whatever your system is
 set to) and run it directly.</p>
@@ -176,11 +176,11 @@ program or do something terribly wrong like slaughtering all the
 <a href="https://www.glyphweb.com/arda/i/imladris.php">Imladris</a>! :-) so please don’t do
 that :-(</p>
 <h3 id="alternate-build">Alternate build:</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="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="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="ex">./anonymous.ten.alt</span></span>
-<span id="cb6-2"><a href="#cb6-2" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb6-3"><a href="#cb6-3" aria-hidden="true" tabindex="-1"></a>    <span class="ex">./anonymous.bed.alt</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./anonymous.ten.alt
+
+    ./anonymous.bed.alt</code></pre>
 <h3 id="a-2023-note-about-the-warning-from-the-author">A 2023 note about the warning from the author:</h3>
 <p>The author suggested that this <em>might</em> somewhat destroy the binaries this
 touches but after the fix of 2023 this was not observed (yet?). It does indeed