Add link to download with docs from GitHub

Created by: lenary

For Bootstrap v1.4 you were very kind and packaged all the documentation along with the framework in one easy zip file. I thought you might do the same for v2.0, so downloaded the zip file again but this time it contained no documentation. Could you please package it again? I can't be the only one that works offline enough that they need to be able to download it with the rest of the resources.