Clean up KeyCloak tutorial #1478
Description
Keycloak changed their URL structure at some point since the last time we took a look at the product, so the docs are out of date.
If we're keeping this tutorial we also need to guide users to mc idp openid accesskey + STS for login instead of the Console, which deprecated support for non-MinIO IAM routes.
Alternatively we can drop Keycloak and redirect up to the OpenID tutorial instead. This is more in keeping with current docs strategies around avoiding third-party applications until such a time as we have the resources to keep them up-to-date with external release cycles.