fix a few more standard header lines in winner README.md files

2019/duble/README.md

@@ -75,6 +75,7 @@ find . -name '.[A-Z]*' -delete
 
 though one might want to check that the program is not currently running. :-)
 
+
 ## Alternate code:
 
 An alternate version of this entry, [prog.alt.c](prog.alt.c), is provided.  This alternate