Add explaination for "These fonts may or may not be included in the repository"

[jdittrich]

I assume that non including these fonts has a reasons like that the license is unclear for us or that it is work in progress (like gidole).
It would be great to include some explanation for not including these fonts – so people new to the repo could see why we did not add those.

[jancborchardt]

The reason that Gidole is in the readme but not in the repo is that we only had the readme in the beginning. So we should actually just add it to the repo. :)