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.

2020/ferguson1/COMPILING.md

@@ -34,7 +34,7 @@ I imagine that it works for 32-bit systems but I do not know for sure.
 You should be able to get the compiler with:
 
 ```sh
-sudo xcode-select --install
+    sudo xcode-select --install
 ```
 
 You don't need Xcode itself and it appears that the command line tools (as above
@@ -54,13 +54,13 @@ recent versions there's the `dnf` package manager but I cannot help with any of
 the GUI installers since I don't use them. Something like:
 
 ```sh
-sudo dnf install ncurses-devel ncurses make gcc
+    sudo dnf install ncurses-devel ncurses make gcc
 ```
 
 or
 
 ```sh
-# dnf install ncurses-devel ncurses make gcc
+    # dnf install ncurses-devel ncurses make gcc
 ```
 
 # Portability: CentOS
@@ -70,25 +70,25 @@ want to use the Makefile `make`). CentOS uses `yum` and CentOS 8 uses `dnf`.
 So:
 
 ```sh
-sudo yum install ncurses-devel ncurses make gcc
+    sudo yum install ncurses-devel ncurses make gcc
 ```
 
 or
 
 ```sh
-# yum install ncurses-devel ncurses make gcc
+    # yum install ncurses-devel ncurses make gcc
 ```
 
 or
 
 ```sh
-sudo dnf install ncurses-devel ncurses make gcc
+    sudo dnf install ncurses-devel ncurses make gcc
 ```
 
 or
 
 ```sh
-# dnf install ncurses-devel ncurses make gcc
+    # dnf install ncurses-devel ncurses make gcc
 ```
 
 You can also use clang to compile (which is what gcc actually is under macOS).