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.

2015/README.md

@@ -67,14 +67,14 @@ and 22 (one third of 666).
 Rule 22, now known as **Catch 22** states:
 
 ```
-|  22) Your source code, data files, remarks and program output must NOT
-|      identify the authors of your code.  The judges STRONGLY prefer to
-|      not know who is submitting entries to the IOCCC.
+    |  22) Your source code, data files, remarks and program output must NOT
+    |      identify the authors of your code.  The judges STRONGLY prefer to
+    |      not know who is submitting entries to the IOCCC.
 
-|      The "Peter Honeyman is exempt" guideline also applies to this rule.
-|      Identifying yourself, in an obvious way in your code, data, remarks
-|      or program output, unless you are Peter Honeyman or pretending
-|      to be Peter Honeyman, will be grounds for disqualification of your entry.
+    |      The "Peter Honeyman is exempt" guideline also applies to this rule.
+    |      Identifying yourself, in an obvious way in your code, data, remarks
+    |      or program output, unless you are Peter Honeyman or pretending
+    |      to be Peter Honeyman, will be grounds for disqualification of your entry.
 ```
 
 A number of other entries were based on [iocccsize.c](iocccsize.c), making
@@ -83,7 +83,7 @@ derivative works rather than original works.
 Still other entries were too large, violating the first line of rule 2:
 
 ```
-2) The size of your program source must be <= 4096 bytes in length.
+    2) The size of your program source must be <= 4096 bytes in length.
 ```
 
 While these entries might have passed under the 2053 limit for iocccsize,