Add AGPL LICENSE
Created by: joshmue
Fixes #1 (closed)
According to https://docs.scs.community/community/license-considerations/, SCS prefers the AGPLv3 license where possible.
Right now, this repository mostly contains a bit of docs/code to use the openstack crossplane provider (Apache-licensed) for the "central-api" use case. Using AGPLv3 here should not (AFAIU, not being a lawyer) infringe the Apache license. In the future, there probably will be more stuff in this repository, making the "central-api" a "SaaS"-like software like Grafana or the SCS statuspage API - making AGPL provisions effective.