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.

1986/marshall/index.html

@@ -132,8 +132,7 @@
 <h2 id="author"><a name="author"></a>Author:</h2>
 <ul>
 <li>Name: <a href="../../authors.html#Eric_Marshall">Eric Marshall</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 -->
@@ -142,7 +141,7 @@ 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>
 <p>NOTE: we FORCE disable the optimiser due to a funny problem with different
 compilers and systems. See below and <a href="compilers.html">compilers.html</a> for details.</p>
 <p>There is an <a href="#alternate-code">alternate version</a>. The reason is a funny problem:
@@ -153,7 +152,7 @@ might work but the other one would not. We describe this in more detail in
 <a href="compilers.html">compilers.html</a> and we encourage you to read it for entertainment
 if nothing else.</p>
 <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">./marshall</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">./marshall</span></span></code></pre></div>
 <h2 id="alternate-code">Alternate code:</h2>
 <p>Due to the different <a href="compilers.html">conflicting problems</a> with gcc and clang, we
 instead offer the problematic code as an alternate version whereas
@@ -161,9 +160,9 @@ instead offer the problematic code as an alternate version whereas
 <code>_exit()</code> commented out, changing the value passed into <code>_exit()</code> to <code>1</code>.</p>
 <h3 id="alternate-build">Alternate build:</h3>
 <p>To see if your compiler has the problems noted:</p>
-<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="fu">make</span> alt</span></code></pre></div>
+<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="fu">make</span> alt</span></code></pre></div>
 <h3 id="alternate-use">Alternate use:</h3>
-<div class="sourceCode" id="cb4"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb4-1"><a href="#cb4-1" aria-hidden="true" tabindex="-1"></a><span class="ex">./marshall.alt</span></span></code></pre></div>
+<div class="sourceCode" id="cb4"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb4-1"><a href="#cb4-1" aria-hidden="true" tabindex="-1"></a>    <span class="ex">./marshall.alt</span></span></code></pre></div>
 <p>Does it work in your system? That is does it not segfault, does it print it only
 once and does it not enter an infinite loop? Or more generally does it print the
 text exactly once and then exit?</p>