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.

1990/baruch/README.md

@@ -30,7 +30,7 @@ echo 3 | ./baruch
 
 Why is there no output?
 
-### Alternate code:
+## Alternate code:
 
 This alternate code is for the [very few](https://en.wikipedia.org/wiki/0)
 [users](https://en.wikipedia.org/wiki/Microsoft_Windows)

1990/westley/README.md

@@ -38,7 +38,7 @@ This program will enter an infinite loop if input is not a number > 0.
 ./westley 5
 ```
 
-### Alternate code:
+## Alternate code:
 
 If you have an old enough compiler try and to see how C has changed over the years: