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.

1989/tromp/index.html

@@ -132,8 +132,7 @@
 <h2 id="author"><a name="author"></a>Author:</h2>
 <ul>
 <li>Name: <a href="../../authors.html#John_Tromp">John Tromp</a><br>
-Location: <a href="../../location.html#US">US</a> - <em>United States of America</em> (<em>United States</em>)
-<br><br></li>
+Location: <a href="../../location.html#US">US</a> - <em>United States of America</em> (<em>United States</em>)</li>
 </ul>
 
 <!-- END: next line ends content generated by: bin/output-index-author.sh -->
@@ -142,13 +141,13 @@ Location: <a href="../../location.html#US">US</a> - <em>United States of America
 <!-- START: this line starts content for HTML phase 21 by: bin/pandoc-wrapper.sh via bin/md2html.sh -->
 
 <h2 id="to-build">To build:</h2>
-<div class="sourceCode" id="cb1"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="fu">make</span> all</span></code></pre></div>
+<div class="sourceCode" id="cb1"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a>    <span class="fu">make</span> all</span></code></pre></div>
 <h2 id="to-use">To use:</h2>
-<div class="sourceCode" id="cb2"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" aria-hidden="true" tabindex="-1"></a><span class="ex">./tromp</span> [drops_per_sec  <span class="pp">[</span><span class="ss">cmd_string</span><span class="pp">]</span>]</span></code></pre></div>
+<div class="sourceCode" id="cb2"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" aria-hidden="true" tabindex="-1"></a>    <span class="ex">./tromp</span> [drops_per_sec  <span class="pp">[</span><span class="ss">cmd_string</span><span class="pp">]</span>]</span></code></pre></div>
 <h2 id="try">Try:</h2>
-<div class="sourceCode" id="cb3"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">./tromp</span> 5</span>
+<div class="sourceCode" id="cb3"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a>    <span class="ex">./tromp</span> 5</span>
 <span id="cb3-2"><a href="#cb3-2" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb3-3"><a href="#cb3-3" aria-hidden="true" tabindex="-1"></a><span class="ex">./tromp</span> 10 <span class="st">&quot;hkl jq&quot;</span></span></code></pre></div>
+<span id="cb3-3"><a href="#cb3-3" aria-hidden="true" tabindex="-1"></a>    <span class="ex">./tromp</span> 10 <span class="st">&quot;hkl jq&quot;</span></span></code></pre></div>
 <p>The second command, <code>./tromp 10 "hkl jq"</code>, will set up the keys kind of like
 vim:</p>
 <ul>
@@ -162,9 +161,9 @@ vim:</p>
 <p>NOTE: after the game ends a file called <code>HI</code> will be in the directory with the
 high scores (up to 20 runs saved) so one can see who has the highest score. The
 file might look like:</p>
-<pre><code>330 by luser
-136 by loser
-100 by winner</code></pre>
+<pre><code>    330 by luser
+    136 by loser
+    100 by winner</code></pre>
 <p>… or so, where in this case the <a href="https://web.archive.org/web/20181023221954/https://www.chicagotribune.com/news/ct-xpm-2002-07-31-0207310310-story.html">luser is the winner, the loser is in second
 place and the winner is the
 loser</a> :-)</p>
@@ -172,7 +171,7 @@ loser</a> :-)</p>
 <p>The author provided an alternate version of the code with some improvements. See
 the judges’ additional remarks in the author’s remarks, for more details.</p>
 <h3 id="alternate-build">Alternate build:</h3>
-<div class="sourceCode" id="cb5"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="fu">make</span> alt</span></code></pre></div>
+<div class="sourceCode" id="cb5"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a>    <span class="fu">make</span> alt</span></code></pre></div>
 <h3 id="alternate-use">Alternate use:</h3>
 <p>Use <code>tromp.alt</code> as you would <code>tromp</code> above.</p>
 <p>NOTE: testing more than one user updating the high score file, one of the