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.

1991/index.html

@@ -155,8 +155,8 @@ a winning entry for the past 5 years!</p>
 would deny awards to more deserving entries. These categories have not
 been eliminated, and will likely be considered in future years.</p>
 <p>A number of entries made use of the following C pre-processor feature:</p>
-<div class="sourceCode" id="cb1"><pre class="sourceCode c"><code class="sourceCode c"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="pp">#define X define</span></span>
-<span id="cb1-2"><a href="#cb1-2" aria-hidden="true" tabindex="-1"></a><span class="pp">#</span><span class="er">X foo bar</span></span></code></pre></div>
+<div class="sourceCode" id="cb1"><pre class="sourceCode c"><code class="sourceCode c"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a>    <span class="pp">#define X define</span></span>
+<span id="cb1-2"><a href="#cb1-2" aria-hidden="true" tabindex="-1"></a>    <span class="pp">#</span><span class="er">X foo bar</span></span></code></pre></div>
 <p>This is not permitted under ANSI C. Some ANSI C compilers do allow this. In
 the future, we do not want programs to use this feature. Because this request
 was not stated in the <a href="rules.txt">1991 rules</a>, we did not reject entries of this
@@ -173,10 +173,10 @@ specific display hardware, or a specific user interface (<code>Openl**k</code>,
 explanation of our viewpoint in next year’s rules.</p>
 <p>In order to encourage more ‘normal’ looking C programs, we are considering
 the following change to the maximum size rule:</p>
-<pre><code>Your source, not counting any &lt;space&gt;, &lt;tab&gt;, and a &lt;newline&gt; character,
-and not counting any &#39;;&#39;, &#39;{&#39; and &#39;}&#39; character followed by a &lt;newline&gt;
-character, must be 1536 bytes or less.  The entire source, counting all
-characters, be 4096 bytes or less.</code></pre>
+<pre><code>    Your source, not counting any &lt;space&gt;, &lt;tab&gt;, and a &lt;newline&gt; character,
+    and not counting any &#39;;&#39;, &#39;{&#39; and &#39;}&#39; character followed by a &lt;newline&gt;
+    character, must be 1536 bytes or less.  The entire source, counting all
+    characters, be 4096 bytes or less.</code></pre>
 <p>Some thought has been given to adding some C++ categories, however this
 is not likely to happen soon. We are waiting until C++ compilers become
 common place on a wide number of systems. We also need time to brace
@@ -186,8 +186,8 @@ We may fine tune the rules to reflect the some ideas above.</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>
 <h2 id="final-comments">Final Comments</h2>
 <p><strong>IMPORTANT NOTE</strong>: The email addresses found above are for historical
 purposes only, and should not be used today. See