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.

2006/toledo3/README.md

@@ -1,7 +1,7 @@
 ## To build:
 
 ```sh
-make
+    make
 ```
 
 The author provided two alternate versions, one which adds a status bar and
@@ -12,14 +12,14 @@ tested with Windows.  See [alternate code](#alternate-code) below.
 ## To use:
 
 ```sh
-./toledo3 [1 | 2 | 3 [b]]
+    ./toledo3 [1 | 2 | 3 [b]]
 ```
 
 
 ## Try:
 
 ```sh
-./toledo3 1
+    ./toledo3 1
 ```
 
 
@@ -63,13 +63,13 @@ Is An IOCCC Entry'). Pointing and clicking to move pieces is the only required
 action, and of course the command-line options:
 
 ```sh
-./toledo3        # Two-players mode (useful if you don't have a board at hand)
-./toledo3 1      # Human white - Computer black, level 1 (fast)
-./toledo3 2      # Human white - Computer black, level 2 (medium)
-./toledo3 3      # Human white - Computer black, level 3 (slow)
-./toledo3 1 b    # Human black - Computer white, level 1 (fast)
-./toledo3 2 b    # Human black - Computer white, level 2 (medium)
-./toledo3 3 b    # Human black - Computer white, level 3 (slow)
+    ./toledo3        # Two-players mode (useful if you don't have a board at hand)
+    ./toledo3 1      # Human white - Computer black, level 1 (fast)
+    ./toledo3 2      # Human white - Computer black, level 2 (medium)
+    ./toledo3 3      # Human white - Computer black, level 3 (slow)
+    ./toledo3 1 b    # Human black - Computer white, level 1 (fast)
+    ./toledo3 2 b    # Human black - Computer white, level 2 (medium)
+    ./toledo3 3 b    # Human black - Computer white, level 3 (slow)
 ```
 
 The computer will check that your moves are legal. Full legal
@@ -98,7 +98,7 @@ Because it is resource-hungry, I strongly recommend to compile it
 using maximum optimization. With GCC you can use:
 
 ```sh
-gcc -O3 -fexpensive-optimizations prog.c -o prog -lX11
+    gcc -O3 -fexpensive-optimizations prog.c -o prog -lX11
 ```
 
 ### KNOWN "FEATURES"