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

2015/burton/README.md

@@ -52,6 +52,7 @@ grep '[0-9]' prog.c
 man ./calc.1
 ```
 
+
 ## Alternate code:
 
 An alternate version of this entry, `prog.alt.c`, is provided.

2015/duble/README.md

@@ -32,6 +32,7 @@ DRAFT=1 ./prog < prog.c
 ./prog < prog.c
 ```
 
+
 ## Alternate code:
 
 An alternate version of this entry, prog.alt.c, is provided.  This alternate

2015/endoh4/README.md

@@ -31,6 +31,7 @@ make
 ./prog $(< Makefile)
 ```
 
+
 ## Alternate code:
 
 An alternate version of this entry, `prog.alt.c`, is provided.\

2015/howe/README.md

@@ -47,6 +47,7 @@ cp war-and-peace.txt nuked.tmp
 ./avgtime.sh 100 ./prog war-and-peace.txt nuked.tmp
 ```
 
+
 ## Alternate code:
 
 An alternate version of this entry, `prog.alt.c`, is provided.