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.

2013/mills/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 [2013 mills bugs](../../bugs.html#2013_mills).
@@ -19,14 +19,14 @@ For more detailed information see [2013 mills bugs](../../bugs.html#2013_mills).
 ## To use:
 
 ```sh
-./mills
+    ./mills
 ```
 
 
 ## Try:
 
 ```sh
-./mills &
+    ./mills &
 ```
 
 While that is running, point your favorite browser at:
@@ -62,7 +62,7 @@ while you are there, click on an ad.  They could use the money.
 It would be possible to fix this by adding
 
 ```c
-n=1,setsockopt(s,SOL_SOCKET,SO_REUSEADDR,&n,sizeof n),
+    n=1,setsockopt(s,SOL_SOCKET,SO_REUSEADDR,&n,sizeof n),
 ```
 
 at an appropriate spot in the code (an exercise left to the reader).  However,