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.

2020/endoh2/README.md

@@ -1,27 +1,27 @@
 ## To build:
 
 ```sh
-make
+    make
 ```
 
 
 ## To use:
 
 ```sh
-./prog
+    ./prog
 ```
 
 
 ## Try:
 
 ```sh
-./try.sh
+    ./try.sh
 ```
 
 What happens if you do
 
 ```sh
-./prog prog.c
+    ./prog prog.c
 ```
 
 ?
@@ -42,11 +42,11 @@ render for a larger terminal window?  How about adding more glyphs?
 No!  Try not.  Do, or do not.  There is no try.
 
 ```sh
-cc -std=c99 prog.c
-./a.out
-./a.out hello.txt
-./a.out yoda.txt
-./a.out bear.txt
+    cc -std=c99 prog.c
+    ./a.out
+    ./a.out hello.txt
+    ./a.out yoda.txt
+    ./a.out bear.txt
 ```
 
 See spoiler.zip for the source code.