come up with a permissions scheme for data set repositories (and document it)

The repository https://gl.kwarc.info/SIGMathLing/dataset-arXMLiv-08-2017/ has permissions "internal", which gives access to all who have an account on gl.kwarc.info. (much too liberal @dginev).

I think the only way of doing this is by making dataset repositories private and giving SIGMathLing members access. I think we should make a group SIGMathLing-members (initially with Deyan, @jfschaefer and me) that has read access to the repositories. Authors (maintainers) can get admin rights individually.