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.

2015/yang/README.md

@@ -1,21 +1,21 @@
 ## To build:
 
 ```sh
-make
+    make
 ```
 
 
 ## To use:
 
 ```sh
-echo Some text | ./prog
+    echo Some text | ./prog
 ```
 
 
 ## Try:
 
 ```sh
-./try.sh
+    ./try.sh
 ```
 
 
@@ -38,24 +38,24 @@ so you need not worry about this.
 her some input through `stdin` to get lots of sea star patterns on `stdout`.
 
 ```sh
-cc -O3 -std=c90 fuuko.c -lm -o fuuko_c90
-echo IOCCC | ./fuuko_c90 > output_c90.c
+    cc -O3 -std=c90 fuuko.c -lm -o fuuko_c90
+    echo IOCCC | ./fuuko_c90 > output_c90.c
 ```
 
 If you compile with a C99 compiler instead of C90, the sea stars will
 have eyes.
 
 ```sh
-cc -O3 -std=c99 fuuko.c -lm -o fuuko_c99
-echo IOCCC | ./fuuko_c99 > output_c99.c
+    cc -O3 -std=c99 fuuko.c -lm -o fuuko_c99
+    echo IOCCC | ./fuuko_c99 > output_c99.c
 ```
 
 Don't like [sea stars](https://en.wikipedia.org/wiki/Starfish)?  Use a C++98
 compiler to get a [dango](https://en.wikipedia.org/wiki/Dango) instead.
 
 ```sh
-g++ -O3 -std=c++98 fuuko.c -lm -o fuuko_cpp98
-echo IOCCC | ./fuuko_cpp98 > output_cpp98.c
+    g++ -O3 -std=c++98 fuuko.c -lm -o fuuko_cpp98
+    echo IOCCC | ./fuuko_cpp98 > output_cpp98.c
 ```
 
 Don't like [dango](https://en.wikipedia.org/wiki/Dango) either?  Use a C++11
@@ -64,16 +64,16 @@ cheese](https://en.wikipedia.org/wiki/Swiss_cheeses_and_dairy_products), if you
 prefer that).
 
 ```sh
-g++ -O3 -std=c++11 fuuko.c -lm -o fuuko_cpp11
-echo IOCCC | ./fuuko_cpp11 > output_cpp11.c
+    g++ -O3 -std=c++11 fuuko.c -lm -o fuuko_cpp11
+    echo IOCCC | ./fuuko_cpp11 > output_cpp11.c
 ```
 
 Don't like any of these patterns?  Use a C11 compiler and there will be
 no extra pattern.
 
 ```sh
-cc -O3 -std=c11 fuuko.c -lm -o fuuko_c11
-echo IOCCC | ./fuuko_c11 > output_c11.c
+    cc -O3 -std=c11 fuuko.c -lm -o fuuko_c11
+    echo IOCCC | ./fuuko_c11 > output_c11.c
 ```
 
 Regardless of which of these C/C++ dialects you choose, the output