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/borsanyi/README.md

@@ -1,7 +1,7 @@
 ## To build:
 
 ```sh
-make
+    make
 ```
 
 
@@ -10,7 +10,7 @@ make
 The current status of this entry is:
 
 ```
-STATUS: INABIAF - please **DO NOT** fix
+    STATUS: INABIAF - please **DO NOT** fix
 ```
 
 For more detailed information see [2006 borsanyi bugs](../../bugs.html#2006_borsanyi).
@@ -19,14 +19,14 @@ For more detailed information see [2006 borsanyi bugs](../../bugs.html#2006_bors
 ## To use:
 
 ```sh
-./borsanyi string > file.gif
+    ./borsanyi string > file.gif
 ```
 
 
 ## Try:
 
 ```sh
-./try.sh
+    ./try.sh
 ```
 
 We recommend you input for the filename `example.gif` and for the string
@@ -69,9 +69,9 @@ used. A typical email address is stored in less than 1-2 kilobytes.
 ### Usage:
 
 ```sh
-make all
-./borsanyi my@example.com > email.gif
-my_favourite_gif_viewer email.gif
+    make all
+    ./borsanyi my@example.com > email.gif
+    my_favourite_gif_viewer email.gif
 ```
 
 The address cannot be longer than 42 characters, and may consist of