Add African country maps

This adds maps for the 8 countries below, which our partner in Zim has requested.

Yes, this does increase the size of the repository (and as a result, the .iso images we distribute for Butter Boxes). But, we plan to migrate to "Content Packs" which will allow anyone to host just the content they need on their box, so these should all go away sometime soon. Just not before the end of this grant.