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.

1985/shapiro/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```sh
+```<!---sh-->
     make all
 ```
 
@@ -10,7 +10,7 @@ There is alternate code which allows one to change the size of the maze. See
 
 ### To run:
 
-```sh
+```<!---sh-->
     ./shapiro
 ```
 
@@ -23,7 +23,7 @@ of the maze. The alt code allows one to easily do this.
 
 ### Alternate build:
 
-```sh
+```<!---sh-->
     make alt
 ```
 
@@ -32,7 +32,7 @@ of the maze. The alt code allows one to easily do this.
 
 If you wish to change the value you can do it like:
 
-```sh
+```<!---sh-->
     make clobber SIZE=5 alt
 ```
 
@@ -41,7 +41,7 @@ error. If it's <= 0 || >= 5000 then it is set to 39, the default.
 
 You might also wish to try:
 
-```sh
+```<!---sh-->
     ./try.alt.sh
 ```
 

1985/shapiro/index.html

@@ -141,23 +141,23 @@ Location: <a href="../../location.html#US">US</a> - <em>United States of America
 <!-- 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> all</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    make all</code></pre>
 <p>There is alternate code which allows one to change the size of the maze. See
 <a href="#alternate-code">Alternate code</a> below.</p>
 <h3 id="to-run">To run:</h3>
-<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">./shapiro</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./shapiro</code></pre>
 <h2 id="alternate-code">Alternate code:</h2>
 <p>The code has a define <code>C</code> set to 39 but this can be modified to change the size
 of the maze. The alt code allows one to easily do this.</p>
 <h3 id="alternate-build">Alternate build:</h3>
-<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="fu">make</span> alt</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    make alt</code></pre>
 <h3 id="alternate-try">Alternate try:</h3>
 <p>If you wish to change the value you can do it like:</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 SIZE=5 alt</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    make clobber SIZE=5 alt</code></pre>
 <p>Note that if it is not a number then obviously there will be a compilation
 error. If it’s &lt;= 0 || &gt;= 5000 then it is set to 39, the default.</p>
 <p>You might also wish to try:</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">./try.alt.sh</span></span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./try.alt.sh</code></pre>
 <p>This script will compile the program five times with a random value and then
 prompt you in an infinite loop for values to try, exiting only if non-digits are
 in the input.</p>