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/imc/index.html

@@ -132,8 +132,7 @@
 <h2 id="author"><a name="author"></a>Author:</h2>
 <ul>
 <li>Name: <a href="../../authors.html#Ian_Collier">Ian Collier</a><br>
-Location: <a href="../../location.html#GB">GB</a> - <em>United Kingdom of Great Britain and Northern Ireland</em> (<em>United Kingdom</em>)
-<br><br></li>
+Location: <a href="../../location.html#GB">GB</a> - <em>United Kingdom of Great Britain and Northern Ireland</em> (<em>United Kingdom</em>)</li>
 </ul>
 
 <!-- END: next line ends content generated by: bin/output-index-author.sh -->
@@ -142,12 +141,12 @@ Location: <a href="../../location.html#GB">GB</a> - <em>United Kingdom of Great
 <!-- 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">./imc</span> <span class="pp">[</span><span class="ss">NUMBER</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">./imc</span> <span class="pp">[</span><span class="ss">NUMBER</span><span class="pp">]</span></span></code></pre></div>
 <p>where <code>[NUMBER]</code> is an optional number. Default is 5.</p>
 <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">./try.sh</span></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="ex">./try.sh</span></span></code></pre></div>
 <h2 id="judges-remarks">Judges’ remarks:</h2>
 <p>This entry’s algorithm is as magic as its output!</p>
 <h2 id="authors-remarks">Author’s remarks:</h2>
@@ -176,9 +175,9 @@ used to make the random squares are quite complex without being shrouded
 in obfuscated code! :-) Incidentally, I was surprised to find out how
 useful the exclusive-or operator was while writing function <code>s()</code>.</p>
 <p>Here are the descriptions of the functions in the library:</p>
-<pre><code>o(n,a,q,d): makes a magic square of order n when n is odd and at least 3.
-s(n,a,q,d): makes a magic square of order n when n equals 4.
-e(n,a,q,d): makes a magic square of order n when n is even and at least 6.</code></pre>
+<pre><code>    o(n,a,q,d): makes a magic square of order n when n is odd and at least 3.
+    s(n,a,q,d): makes a magic square of order n when n equals 4.
+    e(n,a,q,d): makes a magic square of order n when n is even and at least 6.</code></pre>
 <p>In the above, <code>a</code> (of type <code>int *</code>) points to an area of memory in which
 the magic square will be stored and <code>q</code> (also of type <code>int *</code>) points to
 an area of memory of length at least <code>n*sizeof(int)</code> bytes which can be