Document SSO setup for Neuvector

Create documentation to outline how to configure SSO for Keycloak with Neuvector.

Including:

• Any special considerations when creating a Keycloak client
• Instructions and values for configuring an OIDC client

Basic values to add OIDC client from earlier discussion - #8 (comment 1113937)

  values:
    controller:
      secret:
        enabled: true
        data:         
          oidcinitcfg.yaml:
            always_reload: true
            enable: true
            issuer: https://login.dso.mil/auth/realms/baby-yoda
            client_id: platform1_a8604cc9-f5e9-4656-802d-d05624370245_bb8-neuvector
            client_secret: <secret>
            default_role: admin