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.

2005/toledo/README.md

@@ -1,20 +1,20 @@
 ## To build:
 
-```sh
+```<!---sh-->
     make
 ```
 
 
 ## To use:
 
-```sh
+```<!---sh-->
     ./toledo [a ...]
 ```
 
 
 ## Try:
 
-```sh
+```<!---sh-->
     ./toledo a
     ./toledo a b
 ```
@@ -30,7 +30,7 @@ Two alternate versions of this entry, [toledo2.c](toledo2.c) and
 
 To compile the alternate versions:
 
-```sh
+```<!---sh-->
     make alt
 ```
 
@@ -63,7 +63,7 @@ This is a [chess](https://en.wikipedia.org/wiki/Chess) program, it can work in
 two modes: two-players, and one player (always white) against the machine. To
 get the first mode, run the program without arguments:
 
-```sh
+```<!---sh-->
     ./toledo
 ```
 
@@ -71,14 +71,14 @@ The other mode is accessible running the program with one argument
 (5-[ply](https://en.wikipedia.org/wiki/Ply_(game_theory))
 analysis):
 
-```sh
+```<!---sh-->
     ./toledo a
 ```
 
 Two arguments for 6-[ply](https://en.wikipedia.org/wiki/Ply_(game_theory))
 analysis:
 
-```sh
+```<!---sh-->
     ./toledo a b
 ```
 

2005/toledo/index.html

@@ -141,18 +141,18 @@ Location: <a href="../../location.html#MX">MX</a> - <em>United Mexican States</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="ex">./toledo</span> [a ...]</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./toledo [a ...]</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">./toledo</span> a</span>
-<span id="cb3-2"><a href="#cb3-2" aria-hidden="true" tabindex="-1"></a>    <span class="ex">./toledo</span> a b</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./toledo a
+    ./toledo a b</code></pre>
 <h2 id="alternate-code">Alternate code:</h2>
 <p>Two alternate versions of this entry, <a href="toledo2.c">toledo2.c</a> and
 <a href="toledo3.c">toledo3.c</a> are provided.</p>
 <h3 id="alternate-build">Alternate build:</h3>
 <p>To compile the alternate versions:</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> alt</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    make alt</code></pre>
 <h3 id="alternate-use">Alternate use:</h3>
 <p>Use Use <code>toledo2</code> and <code>toledo3</code> as you would <code>toledo</code> above.</p>
 <h2 id="judges-remarks">Judges’ remarks:</h2>
@@ -170,14 +170,14 @@ single function.</p>
 <p>This is a <a href="https://en.wikipedia.org/wiki/Chess">chess</a> program, it can work in
 two modes: two-players, and one player (always white) against the machine. To
 get the first mode, run the program without arguments:</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="ex">./toledo</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./toledo</code></pre>
 <p>The other mode is accessible running the program with one argument
 (5-<a href="https://en.wikipedia.org/wiki/Ply_(game_theory)">ply</a>
 analysis):</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="ex">./toledo</span> a</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./toledo a</code></pre>
 <p>Two arguments for 6-<a href="https://en.wikipedia.org/wiki/Ply_(game_theory)">ply</a>
 analysis:</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="ex">./toledo</span> a b</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./toledo a b</code></pre>
 <p>And each successive argument will analyze one
 <a href="https://en.wikipedia.org/wiki/Ply_(game_theory)">ply</a> more. There is no ply
 limit, but beyond 7 ply is very slow, try it at your own risk and computing