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.

2013/morgan2/README.md

@@ -1,7 +1,7 @@
 ## To build:
 
 ```sh
-make
+    make
 ```
 
 
@@ -10,13 +10,13 @@ make
 For the console version (ncurses):
 
 ```sh
-./morgan2
+    ./morgan2
 ```
 
 For the graphical version (X11):
 
 ```sh
-./morgan2 X
+    ./morgan2 X
 ```
 
 
@@ -133,13 +133,13 @@ simply press `q` when you have finished...
 With gcc 4.7.2 on Linux Ubuntu 12.10 :
 
 ```
-morgan2.c:46:65: warning: value computed is not used [-Wunused-value]
+    morgan2.c:46:65: warning: value computed is not used [-Wunused-value]
 ```
 
 With clang 3.1 on Linux Ubuntu 12.10 :
 
 ```
-morgan2.c:23:24: warning: adding 'int' to a string does not append to the string [-Wstring-plus-int]
+    morgan2.c:23:24: warning: adding 'int' to a string does not append to the string [-Wstring-plus-int]
 ```
 
 **!!!!! HAVE FUN !!!!!**