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.

status.md

@@ -10,7 +10,7 @@ than this comment.  :-)
 
 The JSON member value must be the following JSON quoted string:
 
-```json
+```<!---json-->
     "mandatory comment: because comments were removed from the original JSON spec"
 ```
 
@@ -100,7 +100,7 @@ This shows the latest modification date for the [IOCCC news](news.html) page.
 The JSON member value is a JSON quoted string obtained from the date field
 of the following `ls(1)` command:
 
-```ls
+```<!---ls-->
     TZ=UTC ls -D '%FT%T+00:00' -ld news.html
 ```
 
@@ -118,7 +118,7 @@ This shows the latest modification date [status.json](status.json) file.
 The JSON member value is a JSON quoted string obtained from the date field
 of the following `ls(1)` command:
 
-```ls
+```<!---ls-->
     TZ=UTC ls -D '%FT%T+00:00' -ld status.json
 ```