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.

1998/schnitzi/index.html

@@ -141,28 +141,28 @@ Location: <a href="../../location.html#ZZ">ZZ</a> - <em>Unknown location</em></l
 <!-- 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>
 <h3 id="bugs-and-misfeatures">Bugs and (Mis)features:</h3>
 <p>The current status of this entry is:</p>
 <pre><code>    STATUS: INABIAF - please **DO NOT** fix</code></pre>
 <p>For more detailed information see <a href="../../bugs.html#1998_schnitzi">1998 schnitzi 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">./schnitzi</span> n <span class="op">&gt;</span> sort.c</span>
-<span id="cb3-2"><a href="#cb3-2" aria-hidden="true" tabindex="-1"></a>    <span class="fu">make</span> sort</span>
-<span id="cb3-3"><a href="#cb3-3" aria-hidden="true" tabindex="-1"></a>    <span class="ex">./sort</span></span>
-<span id="cb3-4"><a href="#cb3-4" aria-hidden="true" tabindex="-1"></a>    <span class="co"># enter three numbers, space separated</span></span>
-<span id="cb3-5"><a href="#cb3-5" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb3-6"><a href="#cb3-6" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> x y z <span class="kw">|</span> <span class="ex">./sort</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./schnitzi n &gt; sort.c
+    make sort
+    ./sort
+    # enter three numbers, space separated
+
+    echo x y z | ./sort</code></pre>
 <p>where <code>n</code> and <code>x</code>, <code>y</code> and <code>z</code> are numbers.</p>
 <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></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./try.sh</code></pre>
 <p>What happens if at the command line you don’t specify <code>n</code> numbers that the
 program expects? For instance try:</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="ex">./schnitzi</span> 5 <span class="op">&gt;</span> sort.c</span>
-<span id="cb5-2"><a href="#cb5-2" aria-hidden="true" tabindex="-1"></a>    <span class="fu">make</span> sort</span>
-<span id="cb5-3"><a href="#cb5-3" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb5-4"><a href="#cb5-4" aria-hidden="true" tabindex="-1"></a>    <span class="co"># try running the next command four or five times:</span></span>
-<span id="cb5-5"><a href="#cb5-5" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> 2 5 3 1 <span class="kw">|</span> <span class="ex">./sort</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./schnitzi 5 &gt; sort.c
+    make sort
+
+    # try running the next command four or five times:
+    echo 2 5 3 1 | ./sort</code></pre>
 <p>Why does this happen?</p>
 <h2 id="judges-remarks">Judges’ remarks:</h2>
 <p>This is a beautiful program. How can a program with no conditional (except for
@@ -201,13 +201,13 @@ memory capacity, since the function call stack never goes beyond
 a depth of one.</p>
 <p>So what does it do? Give it an integer <code>(1 &lt; n &lt; 27)</code> on the command
 line, such as</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="ex">./schnitzi</span> 5</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./schnitzi 5</code></pre>
 <p>The output will itself be a lipographic program, one which expects input of
 (in this case) five numbers and prints them out sorted. It sorts
 them, however, using only <code>if/else</code> statements, without arrays or
 looping. To see the resulting program run, redirect the output from
 <code>schnitzi</code> into another file, like this</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="ex">./schnitzi</span> 4 <span class="op">&gt;</span> sort.c</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./schnitzi 4 &gt; sort.c</code></pre>
 <p>and then compile it.</p>
 <h3 id="spoilers-and-hints">Spoilers And Hints:</h3>
 <p>The big key to this program is figuring out what the names of the