Write/complete instructions for dev-preview doc based on steps taken to deploy using dpu-network-operator

Based on the story https://issues.redhat.com/browse/SDN-2509, document all the steps required to deploy using DPU network operator.

While steps have been outlined in https://docs.google.com/document/d/1m3xKFERxI_teUbln3dMVPY_xJ5hPLT3xM6JG_hFNZmI/edit#, this story is about going through that list and not only checking if everything is correct, but also that nothing was left out. This story can be completed after feature freeze