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/thadgavin/README.md

@@ -22,6 +22,7 @@ We recommend that you use the alternate code in modern systems. See the
 
 You can press 'q' at any time to exit.
 
+
 ### Try:
 
 If you have SDL1 installed:
@@ -77,12 +78,14 @@ problem there.
 make all
 ```
 
+
 ### Original use:
 
 ```sh
 ./thadgavin
 ```
 
+
 ### Original try:
 
 If you have SDL1 installed:
@@ -102,7 +105,6 @@ less than dazzling. We could not test this entry in DOS mode.
 
 ## Authors' remarks:
 
-
 ### To use under DOS:
 
 Compile using DJGPP as follows: