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.

2012/vik/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```sh
+```<!---sh-->
     make
 ```
 
@@ -25,38 +25,38 @@ For more detailed information see [2012 vik bugs](../../bugs.html#2012_vik).
 
 To embed text (from file or command line):
 
-```sh
+```<!---sh-->
     ./vik e base.png filename > encodedimg.png
 ```
 
 or
 
-```sh
+```<!---sh-->
     ./vik e base.png SomeRandomText > encodedimg.png
 ```
 
 To extract the embedded text:
 
-```sh
+```<!---sh-->
     ./vik d encodedimg.png
 ```
 
 To embed a PNG into another:
 
-```sh
+```<!---sh-->
     ./vik e base.png source.png > encodedimg.png
 ```
 
 To extract the embedded PNG:
 
-```sh
+```<!---sh-->
     ./vik d encodedimg.png > restored.png
 ```
 
 
 ## Try:
 
-```sh
+```<!---sh-->
     ./try.sh
 ```
 
@@ -68,7 +68,7 @@ For those few who might use Windows this alternate code might work.
 
 ### Alternate build:
 
-```sh
+```<!---sh-->
     make alt
 ```
 
@@ -116,7 +116,7 @@ possible to get the bitmap data from the extracted image, and run it through any
 of the previous winning brainfuck interpreters, but I thought it would be easier
 to include an interpreter in the program to avoid the hassle:
 
-```sh
+```<!---sh-->
     ./vik e ioccc.png chocolate.png > encodedimg.png
     ./vik b encodedimg.png
 ```
@@ -125,7 +125,7 @@ It is of course also possible to embed a
 [brainfuck](https://en.wikipedia.org/wiki/Brainfuck) program as a text file
 (as explained above) and decode it, e.g.:
 
-```sh
+```<!---sh-->
     ./vik e ioccc.png .+[.+] > encodedimg.png
     ./vik b encodedimg.png
 ```
@@ -154,7 +154,7 @@ compile the program on this platform, the following line can be added after
 the variable declarations in the main declaration in order to run
 correctly:
 
-```c
+```<!---c-->
     _setmode(_fileno(stdout), 0x8000);
 ```