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/hou/README.md

@@ -1,20 +1,20 @@
 ## To build:
 
-```sh
+```<!---sh-->
     make
 ```
 
 
 ## To use:
 
-```sh
+```<!---sh-->
     ./hou 'expression'
 ```
 
 
 ## Try:
 
-```sh
+```<!---sh-->
     ./try.sh
 ```
 
@@ -32,7 +32,7 @@ source code. What does it mean?
 
 The calculator obeys the precedence rules and allows parenthesis.
 
-```sh
+```<!---sh-->
     ./hou '1+2*3'
     ./hou '(1+2)*3'
 ```
@@ -41,7 +41,7 @@ What exactly does the text formatting do?
 
 What does this evaluate to in C?
 
-```c
+```<!---c-->
     +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+
 ```
 

2011/hou/index.html

@@ -141,11 +141,11 @@ Location: <a href="../../location.html#CN">CN</a> - <em>People’s Republic of C
 <!-- 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="ex">./hou</span> <span class="st">&#39;expression&#39;</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./hou &#39;expression&#39;</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>
 <p>As the script asks you, what does the last one mean? Can you get it to report a
 different value? Hint: it’s in this file, kind of.</p>
 <h2 id="judges-remarks">Judges’ remarks:</h2>
@@ -154,11 +154,11 @@ warnings under the most strict pedantic mode of gcc and clang.</p>
 <p>The first example, along with the correct result appears in the
 source code. What does it mean?</p>
 <p>The calculator obeys the precedence rules and allows parenthesis.</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="ex">./hou</span> <span class="st">&#39;1+2*3&#39;</span></span>
-<span id="cb4-2"><a href="#cb4-2" aria-hidden="true" tabindex="-1"></a>    <span class="ex">./hou</span> <span class="st">&#39;(1+2)*3&#39;</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./hou &#39;1+2*3&#39;
+    ./hou &#39;(1+2)*3&#39;</code></pre>
 <p>What exactly does the text formatting do?</p>
 <p>What does this evaluate to in C?</p>
-<div class="sourceCode" id="cb5"><pre class="sourceCode c"><code class="sourceCode c"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a>    <span class="op">+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+</span></span></code></pre></div>
+<pre class="&lt;!---c--&gt;"><code>    +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+</code></pre>
 <h3 id="self-documenting-source">Self documenting source</h3>
 <p>Comments would almost be redundant. :-}</p>
 <h3 id="the-ascii-art-is-valid-c-code">The ASCII art is valid C code</h3>