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.

2019/giles/README.md

@@ -1,21 +1,21 @@
 ## To build:
 
 ```sh
-make
+    make
 ```
 
 
 ## To use:
 
 ```sh
-./prog infile.wav outfile.wav
+    ./prog infile.wav outfile.wav
 ```
 
 
 ## Try:
 
 ```sh
-./try.sh
+    ./try.sh
 ```
 
 
@@ -63,8 +63,8 @@ Interesting fact: The size of the program from `./iocccsize -i` is 2019.
 #### How to use:
 
 ```sh
-./prog input [output [size [dry [wet [damping]]]]]
-prog.exe input [output [size [dry [wet [damping]]]]]
+    ./prog input [output [size [dry [wet [damping]]]]]
+    prog.exe input [output [size [dry [wet [damping]]]]]
 ```
 
 * `input`: The path to the input file. Required.
@@ -88,7 +88,7 @@ so it may be a good idea to adjust the ratio of "dry" to "wet", to give a more
 pleasant result:
 
 ```sh
-./prog in.wav out.wav 1.8 80% 15%
+    ./prog in.wav out.wav 1.8 80% 15%
 ```
 
 The program only supports WAV files, and only mostly. Other audio formats, such