Description of problem: CNF / GitOps ZTP Docs

 The "How to use ARM platform hardware in OpenShift 4.19 and above for Telco RDS" KCS https://access.redhat.com/articles/7118870 describes both:  

• ARM Deployment via ZTP Workflow
• ARM Policies / RDS configuration manifests

The official 4.20 Docs have properly included the second bullet point in ths section https://docs.redhat.com/en/documentation/openshift_container_platform/4.20/html/scalability_and_performance/telco-ran-du-ref-design-specs#telco-ran-node-tuning-operator_telco-ran-du but everything related to how to deploy the ARM cluster from an x86 hub cluster is not described - it should also be covered by the official docs. 

Examples of places I would look for this specific information about overriding the InfraEnv with the right ironic image, cpuArchitecture, etc are:

• OCP > Edge Computing > Chapter 9: Advanced ManagedCluster configuration with SiteConfig)
• ACM > Chapter 2.7 > SiteConfig Advanced Topics
• telco-ran github repository: arm-site.yaml example of an ARM architecture managedcluster