set pandoc 8 character tab stops for HTML conversion

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 "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`.

Performed `make www` to perform the above and test under macOS.

2004/kopczynski/index.html

@@ -175,7 +175,7 @@ anything that does not resemble 8, 9, 10, or 11, the result is
 seemingly arbitrary. Actually it is not pseudo-random; can you find
 a pattern when it does not resemble 8, 9, 10 or 11?</p>
 <p>Here is a related puzzle: how to continue the sequence:</p>
-<pre><code>1, 0, 0, 0, 0, 0, 1, 0, 2, 1, ...</code></pre>
+<p>1, 0, 0, 0, 0, 0, 1, 0, 2, 1, …</p>
 <p>With certain arguments, you can alter the exit value / output. Can you figure
 out how and why?</p>
 <h2 id="authors-remarks">Author’s remarks:</h2>
@@ -219,24 +219,24 @@ numbers from 8 to 11.</p></li>
 <li><p>We know that <a href="https://en.wikipedia.org/wiki/Euler_characteristic">Euler
 characteristics</a> is the number of “vertexes”</p></li>
 </ol>
-<pre><code>        #</code></pre>
+<pre><code>            #</code></pre>
 <p>minus the number of “edges”</p>
-<pre><code>       ## # #. .#
-          # .# #.   (&#39;.&#39; must be empty)</code></pre>
+<pre><code>           ## # #. .#
+              # .# #.   (&#39;.&#39; must be empty)</code></pre>
 <p>plus the number of “faces”</p>
-<pre><code>       ##
-       ##</code></pre>
+<pre><code>           ##
+           ##</code></pre>
 <ol start="3" type="1">
 <li>If we fill all these patterns to 2x2 squares,</li>
 </ol>
-<pre><code>       #? ## #? #. .# ##
-       ?? ?? #? .# #. ##
-       +1 -1 -1 -1 -1 +1</code></pre>
+<pre><code>           #? ## #? #. .# ##
+           ?? ?? #? .# #. ##
+           +1 -1 -1 -1 -1 +1</code></pre>
 <p>substitute all possible “values” of <code>?</code> and sum them up, we get that it is
 enough to calculate:</p>
-<pre><code>       #. .# ##
-       .. #. #.
-       +1 -1 -1</code></pre>
+<pre><code>           #. .# ##
+           .. #. #.
+           +1 -1 -1</code></pre>
 <p>Note now it is simple and obfuscated enough to be used as
 a “magic trick”.</p>
 <ol start="4" type="1">
@@ -276,11 +276,11 @@ comes from this. For additional obfuscation and conciseness, <code>if</code> mea
 
     You are free to share and adapt this file under the terms of this license:
 
-    Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
+        Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
 
     For more information, see:
 
-    https://creativecommons.org/licenses/by-sa/4.0/
+        https://creativecommons.org/licenses/by-sa/4.0/
 
 -->
 
@@ -358,7 +358,7 @@ comes from this. For additional obfuscation and conciseness, <code>if</code> mea
 <div class="footer">
   <h2>Copyright and CC BY-SA 4.0 License</h2>
   <p>This file and web page is:</p>
-  <blockquote><p><b>Copyright &copy; 1984-2024 by Landon Curt Noll. All Rights Reserved.</b></p></blockquote>
+  <blockquote><b>Copyright &copy; 1984-2024 by Landon Curt Noll. All Rights Reserved.</b></blockquote>
   <p>You are free to share and adapt this file under the terms of this license:</p>
   <blockquote><b>Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)</b></blockquote>
   <p>For more information, see:</p>