Changing heading level of 'Alternate code'

Change level 3 (###) to level 2 (##):

    sgit -e 's/^### \(Alternate code\)/## \1/g' '*README.md'

which is the same as:

    sgit -e 's/^### Alternate code/## Alternate code/g' '*README.md'

This is per discussion in GitHub.

2012/endoh1/README.md

@@ -32,7 +32,7 @@ this by default.
 
 
 
-### Alternate code:
+## Alternate code:
 
 An alternate version of this entry, `endoh1.alt.c`, is provided.
 This alternate code is a de-obfuscated version of `endoh1.c`.