Proposal for new QIIME 2 community code of conduct

Hi all, Thanks to everyone who took a look through this proposal over the last couple of months. We're going to go live with this new code of conduct in the next few days.

We're going to start by directing violation reports to the qiime2.developers@gmail.com address, which as I noted above goes to multiple developers. We remain open to suggestions about other ways to handle this, and to other input about this community code of conduct.

@devonorourke, thanks for your suggestion regarding transparency through public annual summaries! We're going to see how things go over the first year, and assess whether that's an approach we want to take.

Update: The Code of Conduct is now live in a temporary location and will migrate to a permanent location shortly.