Update index.html

A while back we discussed dropping all but the latest bugfix versions of the docs from the "Other Docs" dropdown, and maybe now would be a good place to do that, if you agree.

After the 0.4 release (and after I've hopefully had time to work on some other priorities) I do plan on developing some new release scripts that could including doing tasks like this automatically.
Merge pull request #1 from embray/patch-1

Update index.html