Improve the display of the home page (see summary)

The home page can be improved in the following ways: 1) More explanation of the project and the directory on home page (or at least prominent links to explanation); 2) A prominent link to more info about the Data Commons Project; 3) Replacing the current banner with a new one that says "cooperative and solidarity economy" (as was agreed a while back) and includes "Data Commons Project" (Ethan has a new banner created-- whoever takes this blueprint should email him to get it); 4) consider a multi-column layout so that these above features don't crowd out the other elements; 5) "latest changes" could be smaller and less central