Ready repository for external contributors

[kshepard]

Overview

The top of the README has a statement mentioning that it is not yet ready for public-use. I believe we've gotten the repository to the point where it is much closer to MVP-ready, and there are only some minor changes needed to allow someone outside of Azavea to get spun up. I think the main barrier is related to our AWS credentials and bucket. If we were to make this configurable and add instructions for a user to set up an AWS account/bucket for data storage, then I think we would be able to remove this README clause. We should also host an example GeoJSON input file, so a user can pull it down, process it, and publish it to their bucket in order to get started.

Acceptance criteria

• README is updated to remove the "not for public use" clause, and have instructions for getting started with development
• The AWS account/bucket is configurable
• An example GeoJSON input file is published with instructions on how to process and publish it for local development use

[dmcglone]

We still need to update the readme with a GeoJSON you can use