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.

2015/dogon/README.md

@@ -1,13 +1,13 @@
 ## To build:
 
-```sh
+```<!---sh-->
     make
 ```
 
 To change the dimensions you can use the `WIDTH` and `HEIGHT` variables when
 compiling (default 1024 x 800):
 
-```sh
+```<!---sh-->
     make clobber WIDTH=640 HEIGHT=480
 ```
 
@@ -22,14 +22,14 @@ code](#alternate-code) below.
 
 ## To use:
 
-```sh
+```<!---sh-->
     ./prog
 ```
 
 
 ## Try:
 
-```sh
+```<!---sh-->
     ./prog
 ```
 
@@ -77,7 +77,7 @@ This alt version does this for you.
 
 ### Alternate build:
 
-```sh
+```<!---sh-->
     make alt
 ```
 
@@ -174,7 +174,7 @@ important support of up to 32 function keys keyboards without spilling over the
 size limit, and allows us to use such fun expression for arrow view control as
 the following:
 
-```c
+```<!---c-->
     *(a&1?&C:&B)-=(.05 -a/2%2*.1)*!(a-1&4092^3920)
 ```
 

2015/dogon/index.html

@@ -141,19 +141,19 @@ 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>
 <p>To change the dimensions you can use the <code>WIDTH</code> and <code>HEIGHT</code> variables when
 compiling (default 1024 x 800):</p>
-<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="fu">make</span> clobber WIDTH=640 HEIGHT=480</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    make clobber WIDTH=640 HEIGHT=480</code></pre>
 <p>to make the game 640 x 480. Obviously changing it to non numbers or negative
 numbers or too large numbers will cause problems.</p>
 <p>There is an alternate version that is based on the author’s suggestion to change
 a value in order to see a bug that they avoided in their entry. See <a href="#alternate-code">Alternate
 code</a> below.</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></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./prog</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">./prog</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./prog</code></pre>
 <p>Press and hold the Left Arrow key until you turn 90-degrees to the left.</p>
 <p>When you see a long tunnel, press the function key F2.</p>
 <p>Use the Up, Down, Left and Right keys to change your path.</p>
@@ -176,7 +176,7 @@ again.</p>
     direction of the main tunnel.</code></pre>
 <p>This alt version does this for you.</p>
 <h3 id="alternate-build">Alternate build:</h3>
-<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">make</span> alt</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    make alt</code></pre>
 <h3 id="alternate-use">Alternate use:</h3>
 <p>Use <code>prog.alt</code> as you would <code>prog</code> above.</p>
 <h3 id="alternate-try">Alternate try:</h3>
@@ -246,7 +246,7 @@ important support of up to 32 function keys keyboards without spilling over the
 size limit, and allows us to use such fun expression for arrow view control as
 the following:</li>
 </ul>
-<div class="sourceCode" id="cb7"><pre class="sourceCode c"><code class="sourceCode c"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a>    <span class="op">*(</span>a<span class="op">&amp;</span><span class="dv">1</span><span class="op">?&amp;</span>C<span class="op">:&amp;</span>B<span class="op">)-=(</span><span class="fl">.05</span> <span class="op">-</span>a<span class="op">/</span><span class="dv">2</span><span class="op">%</span><span class="dv">2</span><span class="op">*</span><span class="fl">.1</span><span class="op">)*!(</span>a<span class="op">-</span><span class="dv">1</span><span class="op">&amp;</span><span class="dv">4092</span><span class="op">^</span><span class="dv">3920</span><span class="op">)</span></span></code></pre></div>
+<pre class="&lt;!---c--&gt;"><code>    *(a&amp;1?&amp;C:&amp;B)-=(.05 -a/2%2*.1)*!(a-1&amp;4092^3920)</code></pre>
 <h3 id="precision-issues">Precision issues:</h3>
 <p>The entry, on purpose, (see the section about SIMD below) does not use enough
 bits of precision, so sometimes the ray will miss the intersection of two voxel