Use OAuth authorization flow for Github to handle adding workflows / org secrets

[BryceStevenWilley]

OAuth is the more standard way for an application to act as / on behalf of a user (as the set_up interview does here), instead of making the user create a single-use PAT.

https://docs.github.com/en/developers/apps/getting-started-with-apps/differences-between-github-apps-and-oauth-apps

[plocket]

Is it appropriate for our tool to be a permanent app on the user's account? It may be more appropriate for organization accounts, though. Also, I'd love to discuss more because I found the GitHub documentation unclear.