First draft docs for:

Describe how to put the pieces together from already existing procedures and some new docs:

• FR3 pre-requisites. Doc should already exist when this feature is documented and only need to be referred:
  • Enable PCI in placement
  • Enable Nova notifications
  • Configure PCI passthrough
  • Configure OTU for PCI passthrough
• New doc for this feature:
  • Describe how to configure the OpenStackControlPlane CR to enable nova notifications in a way that is compatible with the cleanup agent.
  • Describe how to enable deploying the cleanup agent and how to customize its configuration.