Remove SAML IDP instrx from README.md

The README for this project is not the appropriate place for instructions on setting up a SAML IDP for an application. It made sense when OOD was deployed as part of the CoD cluster. Since the OOD deploys are now done external to this cluster and attached to the cluster via cluster hooks defined in the cluster.yml (ansible playbook in rc/hpc-factory), it is safe to remove those SAML IDP instructions from this README.

We need to add this info to rc/hpc-factory because that is where we define the builds and deploys of applications. Users will find value if they can find this kind of information over there.