Move mailing lists to About

Issue Summary

I think that it is odd that the mailing lists page (http://drupal.org/mailing-lists) is in the Developer's handbook since we have mailing lists for all kinds of things, including general support. I propose we move it to the About Drupal handbook instead so it is in a more general location.

I'll move it myself, I just want some feedback that this is OK to do since it is a top-level section.