Build an attribution page on openaddresses.io

[iandees]

Machine generates a JSON file with license information. We should convert that into a single HTML page on our website giving credit to the organizations we pull data from and linking to them when we have a link.

[migurski]

This is a great idea. We have this data already exposed via JSON at https://results.openaddresses.io/latest/licenses.json so this ought to be easy.