GitHub device authorization flow for open authoring?

[davidmreed]

Hello :wave: I'm excited about using StaticCMS to offer open authoring on a new static site I'm about to launch. I'd really like to be able to do this without any server-side infrastructure, even provided by Netlify. It looks to me like this could work if we were to add the Device flow as an authentication option, because no server is required to complete the OAuth flow. Our front end would simply poll GitHub until the user completed the flow.

Would the project be open to this? I'm happy to work on a PR.