Add a note "If you plan to use Vault" as it seems to cu that vault is mandatory for ODF. Reported by: rhn-support-prpandey https://access.redhat.com/documentation/en-us/red_hat_openshift_data_foundation/4.9/html/deploying_openshift_data_foundation_using_bare_metal_infrastructure/preparing_to_deploy_openshift_data_foundation#annotations:2e3d6b6d-3503-40e4-a522-ecf14bcab79e