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.

1998/tomtorfs/README.md

@@ -1,13 +1,13 @@
 ## To build:
 
-```sh
+```<!---sh-->
     make all
 ```
 
 
 ## To use:
 
-```sh
+```<!---sh-->
     ./tomtorfs filename bitwidth polynom reflected init xor
 ```
 
@@ -25,7 +25,7 @@ where:
 
 ## Try:
 
-```sh
+```<!---sh-->
     ./try.sh
 ```
 
@@ -56,7 +56,7 @@ archiver that uses the CRC-32 algorithm.
 
 #### CRC-16:
 
-```sh
+```<!---sh-->
     ./tomtorfs filename 16 1021 0 FFFF 0000
 ```
 
@@ -64,21 +64,21 @@ archiver that uses the CRC-32 algorithm.
 #### CRC-32:
 
 
-```sh
+```<!---sh-->
     ./tomtorfs filename 32 04C11DB7 1 FFFFFFFF FFFFFFFF
 ```
 
 
 #### XMODEM:
 
-```sh
+```<!---sh-->
     ./tomtorfs filename 16 8408 1 0000 0000
 ```
 
 
 #### ARC:
 
-```sh
+```<!---sh-->
     ./tomtorfs filename 16 8005 1 0000 0000
 ```
 

1998/tomtorfs/index.html

@@ -141,9 +141,9 @@ Location: <a href="../../location.html#ZZ">ZZ</a> - <em>Unknown location</em></l
 <!-- 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>
 <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">./tomtorfs</span> filename bitwidth polynom reflected init xor</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./tomtorfs filename bitwidth polynom reflected init xor</code></pre>
 <p>where:</p>
 <pre><code>    filename  : file to calculate the CRC of
     bitwidth  : width of the CRC in bits (decimal)
@@ -152,7 +152,7 @@ Location: <a href="../../location.html#ZZ">ZZ</a> - <em>Unknown location</em></l
     init      : initial value for the CRC (hexadecimal)
     xor       : value to xor the final CRC with (hexadecimal)</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">./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>If you don’t believe the program is correct, try and compare the output
 of the program with the value of CRCs computed by PKZIP or any other
@@ -169,13 +169,13 @@ archiver that uses the CRC-32 algorithm.</p>
     xor       : value to xor the final CRC with (hexadecimal)</code></pre>
 <h3 id="examples">Examples</h3>
 <h4 id="crc-16">CRC-16:</h4>
-<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">./tomtorfs</span> filename 16 1021 0 FFFF 0000</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./tomtorfs filename 16 1021 0 FFFF 0000</code></pre>
 <h4 id="crc-32">CRC-32:</h4>
-<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">./tomtorfs</span> filename 32 04C11DB7 1 FFFFFFFF FFFFFFFF</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./tomtorfs filename 32 04C11DB7 1 FFFFFFFF FFFFFFFF</code></pre>
 <h4 id="xmodem">XMODEM:</h4>
-<div class="sourceCode" id="cb8"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" aria-hidden="true" tabindex="-1"></a>    <span class="ex">./tomtorfs</span> filename 16 8408 1 0000 0000</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./tomtorfs filename 16 8408 1 0000 0000</code></pre>
 <h4 id="arc">ARC:</h4>
-<div class="sourceCode" id="cb9"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a>    <span class="ex">./tomtorfs</span> filename 16 8005 1 0000 0000</span></code></pre></div>
+<pre class="&lt;!---sh--&gt;"><code>    ./tomtorfs filename 16 8005 1 0000 0000</code></pre>
 <h3 id="portability-notes">Portability notes</h3>
 <p>The program assumes <code>CHAR_BIT==8</code>. Results are undefined if <code>bitwidth &gt; sizeof(unsigned long) * 8</code>. It is also assumed that <code>EOF</code> is <code>-1</code> and <code>1</code> is a
 valid exit value to indicate failure (replace them with <code>EOF</code> resp.