fix Alternate code heading in winner README.md files

1986/wall/README.md

@@ -17,7 +17,8 @@ make all
 ./wall
 ```
 
-### Alternate code:
+
+## Alternate code:
 
 If you have an old compiler or a compiler that supports `-traditional-cpp` you
 might enjoy looking at the original source in [wall.alt.c](wall.alt.c).

1994/horton/README.md

@@ -25,7 +25,8 @@ make all
 ./horton 3 2 1 0
 ```
 
-### Alternate code:
+
+## Alternate code:
 
 This confuses cb greatly. See [horton.alt.c](horton.alt.c) for an unobfuscated/enhanced
 version. To run this alternate version:

1994/tvr/README.md

@@ -30,6 +30,7 @@ make all
 
 Mode may be a value from 0 to 12.
 
+
 ## Alternate code:
 
 The author has provided us a spoiler version:

1994/weisberg/README.md

@@ -21,7 +21,8 @@ make all
 ./weisberg
 ```
 
-### Alternate code:
+
+## Alternate code:
 
 If you liked what you saw from the above program, and happen to
 have some 512 Megabytes of virtual memory lying around with to do,