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.

2014/vik/README.md

@@ -31,7 +31,7 @@ echo 'Want to hear me beep?' | ./prog > audio_file.raw
 echo 'No. I want chocolate!' | ./prog | mplayer -demuxer rawaudio -
 ```
 
-### Alternate code:
+## Alternate code:
 
 The alternate code, [prog.alt.c](prog.alt.c), is based on the author's
 instructions on how to get it to work with Windows. This has not been tested but