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.

1994/index.html

@@ -175,7 +175,7 @@ able to link to the other IOCCC judges by some form of a video link</li>
 <li>loves chocolate and other fine foods :-)</li>
 </ul>
 <p>If you think this may be you, send an email before 31 Dec 1995, to:</p>
-<pre><code>judges@toad.com         (use the Subject: 3rd judge)</code></pre>
+<pre><code>    judges@toad.com             (use the Subject: 3rd judge)</code></pre>
 <p>Include in your message:</p>
 <ul>
 <li>Your name, address, email address and phone number</li>
@@ -190,7 +190,7 @@ email at the above address.</p>
 If you have a well known stable site that would be willing to give us
 access to put up some IOCCC html pages, please send an email (say prior
 to 31 Dec 1995) to:</p>
-<pre><code>judges@toad.com         (use the Subject: www site)</code></pre>
+<pre><code>    judges@toad.com             (use the Subject: www site)</code></pre>
 <p>describing your site and any other appropriate comments. Thanks!</p>
 <h2 id="a-few-notes-regarding-future-contests">A few notes regarding future contests</h2>
 <p>Due to changes in the USENIX conference calendar, the 1995 contest will
@@ -205,8 +205,8 @@ Rules differ from year to year, sometimes in significant ways.</p>
 <p>Please send us comments and suggestions what we have expressed above.
 Also include anything else that you would like to see in future contests.
 Send such email to:</p>
-<pre><code>...!{sun,pacbell,uunet,pyramid}!hoptoad!judges
-judges@toad.com</code></pre>
+<pre><code>    ...!{sun,pacbell,uunet,pyramid}!hoptoad!judges
+    judges@toad.com</code></pre>
 <p>If you use, distribute or publish these entries in some way, please drop
 us a line. We enjoy seeing who, where and how the contest is used,
 as well as details on how to provide fixes to any of the entries.</p>