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.

1992/kivinen/index.html

@@ -142,7 +142,7 @@ Location: <a href="../../location.html#FI">FI</a> - <em>Republic of Finland </em
 
 <h2 id="to-build">To build:</h2>
 <p>If your machine support the X Window System, Version 11:</p>
-<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> alt</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    make alt</code></pre>
 <p>We recommend that you try the alt version first so you can get a better idea of
 what this looked like back in 1992. See <a href="#original-code">original code</a> for the
 original should you wish to see what we mean.</p>
@@ -151,25 +151,25 @@ original should you wish to see what we mean.</p>
 <pre><code>    STATUS: known bug - please help us fix</code></pre>
 <p>For more detailed information see <a href="../../bugs.html#1992_kivinen">1992 kivinen 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">./kivinen.alt</span></span>
-<span id="cb3-2"><a href="#cb3-2" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb3-3"><a href="#cb3-3" aria-hidden="true" tabindex="-1"></a>    <span class="ex">./kivinen.alt</span> a</span>
-<span id="cb3-4"><a href="#cb3-4" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb3-5"><a href="#cb3-5" aria-hidden="true" tabindex="-1"></a>    <span class="ex">./kivinen.alt</span> a b</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./kivinen.alt
+
+    ./kivinen.alt a
+
+    ./kivinen.alt a b</code></pre>
 <p>See also the author’s remarks for other variations.</p>
 <h2 id="try">Try:</h2>
 <p>Also try changing the speed that the game moves. For instance if you wish to
 change the <code>usleep(3)</code> value to <code>30000</code> from <code>20000</code>, try:</p>
-<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> clobber SLEEP=30000 alt <span class="co"># make it slower</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="fu">make</span> clobber SLEEP=10000 alt <span class="co"># make it faster</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    make clobber SLEEP=30000 alt # make it slower
+
+    make clobber SLEEP=10000 alt # make it faster</code></pre>
 <p>Then use the same syntax as above and described by the author.</p>
 <h2 id="original-code">Original code:</h2>
 <p>As noted above, the alt version is recommended because the code goes too fast in
 modern systems. If you wish to see the original you may do so with the original
 code.</p>
 <h3 id="original-build">Original 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> all</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    make all</code></pre>
 <h3 id="original-use">Original use:</h3>
 <p>Use <code>kivinen</code> as you would <code>kivinen.alt</code>.</p>
 <h2 id="judges-remarks">Judges’ remarks:</h2>