Add API Documentation

This PR moves what is our only source of documentation currently to a more standard format.

Current documentation: https://gist.github.com/brittballard/5467db79db48499d17e5

This specifies the one current endpoint.

It also has stubs in place for the APIs that we would need for explore in their basic form to be able to pull down the parameters the API accepts.

There are more endpoints I would like to add for the future but I'd like to put those in for PRs just to give a basic idea of the API and let you merge them as you have added the endpoints so that the documentation represents the current state of the API.