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.

1991/davidguy/README.md

@@ -1,14 +1,14 @@
 ## To build:
 
 ```sh
-make all
+    make all
 ```
 
 
 ## To use:
 
 ```sh
-./davidguy ip_address:server.screen
+    ./davidguy ip_address:server.screen
 ```
 
 where `ip_address` in an IP address of an X server.
@@ -17,7 +17,7 @@ where `ip_address` in an IP address of an X server.
 ## Try:
 
 ```sh
-./davidguy 127.0.0.1:0.0
+    ./davidguy 127.0.0.1:0.0
 ```
 
 Of course, you may need to supply a more reasonable address.  :-)
@@ -25,8 +25,8 @@ Of course, you may need to supply a more reasonable address.  :-)
 ## Also try:
 
 ```sh
-cp -f davidguy guydavid
-./guydavid 127.0.0.1:0.0
+    cp -f davidguy guydavid
+    ./guydavid 127.0.0.1:0.0
 ```
 
 Can you determine why this makes a difference?