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.

2018/algmyr/index.html

@@ -141,7 +141,7 @@ 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>To use this entry requires, in some invocations, a sound processing program.
 This can be ALSA or SoX but we recommend the latter. See <a href="../../faq.html#sox">FAQ 3.10 - How do I
 compile and use an IOCCC entry that requires sound?</a>.</p>
@@ -150,11 +150,11 @@ compile and use an IOCCC entry that requires sound?</a>.</p>
 <pre><code>    STATUS: INABIAF - please **DO NOT** fix</code></pre>
 <p>For more detailed information see <a href="../../bugs.html#2018_algmyr">2018 algmyr 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">./prog</span> <span class="op">&lt;</span> prog.c                     <span class="co"># Print garbage: might mess up your terminal</span></span>
-<span id="cb3-2"><a href="#cb3-2" aria-hidden="true" tabindex="-1"></a>    <span class="ex">./prog</span> <span class="op">&lt;</span>file1<span class="op">&gt;</span> <span class="op">&lt;</span>file2<span class="op">&gt;</span> <span class="op">&gt;</span> out.raw</span>
-<span id="cb3-3"><a href="#cb3-3" aria-hidden="true" tabindex="-1"></a>    <span class="ex">./prog</span> <span class="at">-d</span> 2 0 out.raw               <span class="co"># Decode the first (0th) channel out of two</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./prog &lt; prog.c                     # Print garbage: might mess up your terminal
+    ./prog &lt;file1&gt; &lt;file2&gt; &gt; out.raw
+    ./prog -d 2 0 out.raw               # Decode the first (0th) channel out of two</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></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./try.sh</code></pre>
 <h2 id="judges-remarks">Judges’ remarks:</h2>
 <p>Be warned, this is not your garden variety text-to-speech program! Earplugs are advised,
 or at least a handy and well-tested volume knob.</p>
@@ -242,14 +242,14 @@ additional logic? Answer: <code>ungetc(3)</code> into <code>stdin</code>, one <c
 standards compliant). This is used to print the usage instructions.</p>
 <h3 id="compilation-warnings">Compilation warnings</h3>
 <p>Compiling using</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">gcc</span> <span class="at">-Wall</span> <span class="at">-Wextra</span> <span class="at">-pedantic</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    gcc -Wall -Wextra -pedantic</code></pre>
 <p>gives only <code>-Wmisleading-indentation</code> which is sensible considering the source code. While</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">clang</span> <span class="at">-Wall</span> <span class="at">-Wextra</span> <span class="at">-pedantic</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    clang -Wall -Wextra -pedantic</code></pre>
 <p>is a bit more pessimistic and gives <code>-Wempty-body</code> (I like loops without
 bodies), <code>-Wstring-plus-int</code> (since apparently some people think string+<code>int</code> is a
 concatenation) and one of the weirder warnings I have seen from me splitting a
 negative constant with whitespace. Compiling using</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">clang</span> <span class="at">-Wall</span> <span class="at">-Wextra</span> <span class="at">-pedantic</span> <span class="at">-Weverything</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    clang -Wall -Wextra -pedantic -Weverything</code></pre>
 <p>produces a few page faults of warnings and makes me feel generally bad about
 myself. :(</p>
 <h3 id="misc">Misc</h3>