citing em geosci

[lheagy]

We should include a description for how people should cite EM geosci. I suggest we do something similar to astropy which starts the citation with "Astropy collaboration" and then lists all contributors. Listing contributors is a bit of a question, but on option is to list all who have contributed on github as authors. Note that we should first get permission from everyone. If we treat it like a book, then we can also reference editors if that makes sense? The doi is then the doi from zenodo.

Thoughts?