new short paper on software citation

[danielskatz]

http://arxiv.org/abs/2103.06681

[sdruskat]

Should this go in the outputs list in the README? What is our policy regarding the inclusion of works published by a subgroup of this group?

[danielskatz]

I don't think this is really a group output, but if we had a list of other interesting/topical papers, we could put it there.