Update documentation for required WMCO subscription

User story

As an OpenShift Admin, I want to clearly understand the required subscriptions for WMCO so that I can obtain Red Hat support.

Description

The existing documentation is unclear that a specific subscription is required for support for Windows containers.

Updates should include something similar to:

A subscription as per https://access.redhat.com/support/policy/updates/openshift#windows needs to be available to receive support for the Red Hat WMCO and use it in production environments.

Examples needing clarification:

• https://docs.openshift.com/container-platform/4.9/windows_containers/windows-containers-release-notes-4-x.html#getting-support
• https://github.com/openshift/windows-machine-config-operator/blob/7c86cbe5179477953909cbe9862ba53d80ada8e4/config/manifests/bases/windows-machine-config-operator.clusterserviceversion.yaml#L29-L34
• https://github.com/openshift/windows-machine-config-operator/blob/7c86cbe5179477953909cbe9862ba53d80ada8e4/config/manifests/bases/windows-machine-config-operator.clusterserviceversion.yaml#L135

Engineering Details

See the second part of this thread for context. https://coreos.slack.com/archives/CM4ERHBJS/p1648789414418059

Acceptance Criteria

• Operator description in the CSV is updated to include subscription reference to required 'OpenShift Container Platform for Windows Containers' subscription.
• User docs updated same as above.