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.

2013/cable1/index.html

@@ -174,7 +174,7 @@ Why late? Because:</p>
 An important 2023 update about twitter:</p>
 <p>The IOCCC no longer uses twitter. Today the IOCCC uses Mastodon.
 For more information and to see our IOCCC Mastodon posts, see:</p>
-<pre><code>https://fosstodon.org/@ioccc</code></pre>
+<p>https://fosstodon.org/<span class="citation" data-cites="ioccc">@ioccc</span></p>
 <p>End of important 2023 update to this historic note.
 -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-</p>
 <p>So how does a one line C source know so much? Hint: it doesn’t.</p>
@@ -210,11 +210,11 @@ function declarations are invalid in C99 (but still accepts them).</p>
 
     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/
 
 -->
 
@@ -278,7 +278,7 @@ function declarations are invalid in C99 (but still accepts them).</p>
 <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>