Fix tmp/format-headers.sh, format headers

The script had "s surrounding the git ls-files command which turned it
to a single file which of course is wrong.

Ran script again fixing many README.md files that had incorrect number
of blank lines for critical headers.

This will have to be done a final but a good number of files have been
corrected.

2000/primenum/README.md

@@ -45,7 +45,6 @@ it successfully fooled half of the judges, including me.
 
 ## Author's remarks:
 
-
 ### Description
 
 For 15 years, IOCCC winners have obfuscated programs using esoteric,