Improve interactions with Zotero: Automatic update, sharing, pull requests

Econ-ARK has a Zotero account that is populated with a set of papers that we have used or cited in Econ-ARK projects. We would like:

1. To figure out how to make this usable to anyone who wants to import from it;
1. To figure out how to periodically auto-import from a bibfile at a url on the web;
1. To figure out how to make it really easy for people to propose to add papers to it
1. To have instructions for people to set up their anaconda installation so that when they open Jupyter notebooks locally, the links to our database will work
* I think this is just a matter of setting up the right requirements.txt and notebook extensions

PS. This was formerly a subthread on econ-ark/OverARK#39 but is really a separate issue

Start with the Zotero account, the proposed bibfile URL workflow, and the local Jupyter notebook setup described in the issue. Check the requirements.txt and notebook extensions mentioned; no specific files or tests are named. Done means import, periodic updates, paper proposals, and working notebook links each have an agreed implementation and user instructions.

Written by the indexing model from the issue text.