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.

2004/hoyle/README.md

@@ -24,7 +24,7 @@ make
 ./hoyle 2 0 1 0 -0.001
 ```
 
-### Alternate code:
+## Alternate code:
 
 An alternate version of this entry, [hoyle.alt.c](hoyle.alt.c), is provided.
 This alternate code has a missing newline and used a non-standard tab stop size.