fix standard headers and header spacing in winner README.md files

1989/vanb/README.md

@@ -14,13 +14,15 @@ US
 make all
 ```
 
-## Try:
+
+### Try:
 
 ```sh
 ./vanb the rug gary lent
 ./vanb unix is better than os/2
 ```
 
+
 ## Judges' remarks:
 
 This program computes all proper subsets of the set of
@@ -28,7 +30,6 @@ arguments passed to it.  Each subset is printed with one
 element on each line, followed by a line of ten dashes.
 
 
-
 ## Author's remarks:
 
 The program has the following charming and possibly
@@ -43,6 +44,7 @@ non-portable features:
 * It uses the fact that if the high bit is set in a character variable, the
 value is negative.
 
+
 ## Copyright and CC BY-SA 4.0 License:
 
 This file is Copyright (c) 2023 by Landon Curt Noll.  All Rights Reserved.