move fix thanks a file, update top level html links, rename CONTRIBUTING.md

The fix thank you's have been moved from `README.md` to
`thanks-for-fixes.md`.

**WARNING**: Some mistakes may have been made in doing this.
We presume later changes by others will correct any issues.

The `CONTRIBUTING.md` was renamed `how-to-enter.md`.

A 3rd line of links was added to top level html such as
`contact.html`, `index.html`, `judges.html`, `winners.html`,
and `years.html`.

Improved blank line use in a number (but not all) `README.md` files.

2000/dlowe/README.md

@@ -4,6 +4,7 @@ David Lowe
 US  
 <https://github.com/dlowe>
 
+
 ## To build:
 
 ```sh
@@ -16,11 +17,6 @@ The following bit of perl may help determining the values you need:
 perl -MConfig -e 'print "$Config{archlibexp}/CORE\n"'
 ```
 
-[Cody Boone Ferguson](/winners.html#Cody_Boone_Ferguson) fixed this to compile
-with more recent perl versions; the symbol now `PL_na` was once `na`. He notes
-that this entry crashes under macOS but it works under linux after this change.
-Thank you Cody for your assistance!
-
 
 ## To run:
 
@@ -34,6 +30,7 @@ Thank you Cody for your assistance!
 echo "13 14 15 16 17 + - * / p" | ./dlowe
 ```
 
+
 ## Judges' remarks:
 
 When this entry was submitted the rules of the IOCCC did not prohibit
@@ -49,6 +46,7 @@ The judges' remarks contain a clue to the hidden command :-).
 * The IOCCC uses an anonymous judging process which keeps the identity
 of the submitters hidden until all the prize winners have been selected.
 
+
 ## Author's remarks:
 
 ### Usage
@@ -277,6 +275,7 @@ Also, Perl 5 is bundled with the following OS distributions: AIX 4.3.3+,
 FreeBSD 3.0+, IRIX 6.4+, every Linux distribution, NetBSD, OpenBSD, and
 DEC Tru64 5.0+, again according to the Perl people.
 
+
 ## Copyright and CC BY-SA 4.0 License:
 
 This file is Copyright (c) 2023 by Landon Curt Noll.  All Rights Reserved.