Define requirements for PyHC "affiliation"

[jibarnum]

In order to move forward with the PyHC - pyOpenSci partnership, we need to define what additional community requirements we want of packages going through the review process. These likely include some of the things listed out for package tiers in PHEP 4's PR, but want to collect some ideas here before writing a full PHEP.

[jibarnum]

pyOpenSci page on community partnerships: https://www.pyopensci.org/software-peer-review/partners/scientific-communities.html