Support for OIDC providers which expose .well-known/openid-configuration #89
Description
I was sad to see that the closest thing currently available is the Keycloak provider however that mandates usage of a realm. Many OIDC providers providers, especially FOSS ones which you can self-host provide a standardized well-known/openid-configuration endpoint where all further endpoints and supported values are exposed. It would be great to support this and would eliminate the need for many specialized providers. Ideally, there is a general manualOIDC provider where one can manually set the authorization/token/userinfo/revokation etc endpoint and one wellKnownOIDC provider which simply takes a single URL, fetches the values and delegates the rest to the manualOIDC provider.