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.

2011/goren/README.md

@@ -1,20 +1,20 @@
 ## To build:
 
-```sh
+```<!---sh-->
     make
 ```
 
 
 ## To use:
 
-```sh
+```<!---sh-->
     echo "some text" | ./goren
 ```
 
 
 ## Try:
 
-```sh
+```<!---sh-->
     ./try.sh
 ```
 
@@ -27,13 +27,13 @@ In the words of [René François Ghislain Magritte Magritte](http://en.wikipedia
 
 One may ask the surrealist question:
 
-```sh
+```<!---sh-->
     echo 'If | is just a representation of a pipe, then how can data stuff it?' | ./goren
 ```
 
 However if one takes a firm stand and declares:
 
-```sh
+```<!---sh-->
     echo '| is just a representation of a pipe because I say so! So stuff it!' | ./goren
 ```
 

2011/goren/index.html

@@ -141,11 +141,11 @@ Location: <a href="../../location.html#IL">IL</a> - <em>State of Israel</em> (<e
 <!-- 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>
 <h2 id="to-use">To use:</h2>
-<div class="sourceCode" id="cb2"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="st">&quot;some text&quot;</span> <span class="kw">|</span> <span class="ex">./goren</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    echo &quot;some text&quot; | ./goren</code></pre>
 <h2 id="try">Try:</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">./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>In the words of <a href="http://en.wikipedia.org/wiki/Rene_Magritte">René François Ghislain Magritte Magritte</a>:</p>
 <figure>
@@ -153,9 +153,9 @@ Location: <a href="../../location.html#IL">IL</a> - <em>State of Israel</em> (<e
 <figcaption aria-hidden="true">This is not a pipe</figcaption>
 </figure>
 <p>One may ask the surrealist question:</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="bu">echo</span> <span class="st">&#39;If | is just a representation of a pipe, then how can data stuff it?&#39;</span> <span class="kw">|</span> <span class="ex">./goren</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    echo &#39;If | is just a representation of a pipe, then how can data stuff it?&#39; | ./goren</code></pre>
 <p>However if one takes a firm stand and declares:</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="bu">echo</span> <span class="st">&#39;| is just a representation of a pipe because I say so! So stuff it!&#39;</span> <span class="kw">|</span> <span class="ex">./goren</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    echo &#39;| is just a representation of a pipe because I say so! So stuff it!&#39; | ./goren</code></pre>
 <p>something happens! Why?</p>
 <h2 id="authors-remarks">Author’s remarks:</h2>
 <p>This program was written in homage to <a href="http://en.wikipedia.org/wiki/Rene_Magritte">Rene