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.

1988/westley/README.md

@@ -1,6 +1,6 @@
 ## To build:
 
-```sh
+```<!---sh-->
     make all
 ```
 
@@ -11,13 +11,13 @@ might wish to do so.
 
 ## Try:
 
-```sh
+```<!---sh-->
     ./westley
 ```
 
 Also try:
 
-```sh
+```<!---sh-->
     ./try.sh
 ```
 
@@ -31,7 +31,7 @@ This version is the original which might not work as you expect nowadays.
 
 ### Alternate build:
 
-```sh
+```<!---sh-->
     make alt
 ```
 
@@ -41,7 +41,7 @@ This version is the original which might not work as you expect nowadays.
 To see if your compiler has the problem described in the Judges' remarks below,
 try:
 
-```sh
+```<!---sh-->
     ./westley.alt
 ```
 
@@ -52,7 +52,7 @@ Does it show the same output as `westley`?
 
 Your compiler must parse
 
-```c
+```<!---c-->
     #define _ -a
     -_
 ```
@@ -62,7 +62,7 @@ conforming ANSI C Preprocessors may object to this: for such
 compilers, you can elide the non-standard token-pasting requirement
 by changing the #define line to:
 
-```c
+```<!---c-->
     #define _ F-->00||F-OO--;
 ```
 
@@ -71,7 +71,7 @@ code is the original.
 
 You might enjoy looking at the output of:
 
-```sh
+```<!---sh-->
     cc -E westley.alt.c
 ```