improved indentation and whitespace for markdown code blocks

All code blocks in markdown have been intended by at least 4 spaces.

We add `--tab-stop=8` to all `pandoc(1)` executions in order to set
a better tab stop indentation, especially for tab intended code blocks.

Changed `bin/pandoc-wrapper.sh` VERSION from "1.5.3 2024-03-26"
to "1.6 2024-03-31".

Fixed `1991/brnstnd/sorta.README.md` so that the sorta code
is code blocks.

Removed unneeded paragraph group in copyright in `inc/footer.default.html`.

Fixed excess whitespace after list Author on entry `index.html` page.

Changed `bin/output-index-author.sh` VERSION from "1.5.2 2024-03-26"
to "1.6 2024-03-31".

Performed `make www` to perform the above and test under macOS.

TODO: Fix the problem of the initial line of code being extra intended.
TODO: Fix excess whitespace around code that is inline.

1987/korn/README.md

@@ -1,14 +1,14 @@
 ## To build:
 
 ```sh
-make all
+    make all
 ```
 
 
 ## To use:
 
 ```sh
-./korn
+    ./korn
 ```
 
 
@@ -30,14 +30,14 @@ Several points are important to understand this program:
 characters, or `'h'`, or a string)  Consider the fact that:
 
 ```c
-char *x;
+    char *x;
 ```
 
 defines a pointer to a `char` (i.e. an address), and that the `=` assigns
 things of compatible types.  Since:
 
 ```c
-x = "have";
+    x = "have";
 ```
 
 is legal C, what type of value is `"have"`?
@@ -45,13 +45,13 @@ is legal C, what type of value is `"have"`?
 3. Note that the following expressions yield the same value:
 
 ```c
-x[3]	*(x+3)	  *(3+x)
+    x[3]	*(x+3)	  *(3+x)
 ```
 
 since addition is commutative.  What can be said about this value?
 
 ```c
-3[x]
+    3[x]
 ```
 
 [David