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

2020/burton/README.md

@@ -46,6 +46,7 @@ For more detailed information see [2020 burton in bugs.md](/bugs.md#2020-burton)
 ./prog 128 128 128 128
 ```
 
+
 ## Alternate code:
 
 By default, this code compiles for Little Endian machines.

2020/endoh1/README.md

@@ -32,6 +32,7 @@ make
 ./prog unwinnable.txt
 ```
 
+
 ## Alternate code:
 
 An alternate version of this entry, [prog.alt.c](prog.alt.c), is provided.  This

2020/endoh3/README.md

@@ -26,6 +26,7 @@ make
 # And watch closely for 15-20 seconds
 ```
 
+
 ## Alternate code:
 
 An alternate version of this entry, `prog.alt.c`, is provided.  This alternate code uses Unicode letters.

2020/kurdyukov1/README.md

@@ -28,6 +28,7 @@ echo IOCCC | ./prog
 ./prog < prog.x86_64.asm
 ```
 
+
 ## Alternate code:
 
 An even smaller alternate version of this entry, prog.alt.c, is provided.  This code does not contain any headers, nor any workaround for WIN32 based platforms.

2020/kurdyukov3/README.md

@@ -31,6 +31,7 @@ echo International Obfuscated C Code Contest | ./prog
 ./prog < input.txt
 ```
 
+
 ## Alternate code:
 
 There is an alternate version of this code in `prog.alt.c` where the main code is a macro.