Users can import an existing OCP cluster to the infrastructure-operator in order to add nodes to that cluster.

Create an informative issue (See each section, incomplete templates/issues won't be triaged)

Using the current documentation as a model, please complete the issue template. 

Prerequisite: Start with what we have

Always look at the current documentation to describe the change that is needed. Use the source or portal link for Step 4:

 - Use the Customer Portal: https://access.redhat.com/documentation/en-us/red_hat_advanced_cluster_management_for_kubernetes

 - Use the GitHub link to find the staged docs in the repository: https://github.com/stolostron/rhacm-docs 

Describe the changes in the doc and link to your dev story

Provide info for the following steps:

1. - [x] Mandatory Add the required version to the Fix version/s field.

2. - [x] Mandatory Choose the type of documentation change.

      - [x] New topic in an existing section or new section
      - [ ] Update to an existing topic

3. - [ ] Mandatory for GA content:
            
       - [x] Add steps and/or other important conceptual information here: 
In the upstream doc link https://github.com/openshift/assisted-service/blob/290cea4b5f5bb10724d455a975e4da83e48ca8ef/docs/hive-integration/import-installed-cluster.md
       
            
       - [ ] Add Required access level for the user to complete the task here:
       

       - [x] Add verification at the end of the task, how does the user verify success (a command to run or a result to see?)
     Cluster should be available to add nodes
     
       - [ ] Add link to dev story here:

4. - [x] Mandatory for bugs: What is the diff? Clearly define what the problem is, what the change is, and link to the current documentation:

I'd imagine we'd want to add something in https://access.redhat.com/documentation/en-us/red_hat_advanced_cluster_management_for_kubernetes/2.8/html/clusters/cluster_mce_overview#importing-a-target-managed-cluster-to-the-hub-cluster about how to also manage an imported cluster using the infrastructure-operator, but I'm not sure what the best way to do that would be since we don't have anything about the infrastructure operator in there today.

Currently most of the infrastructure operator related docs are in https://access.redhat.com/documentation/en-us/red_hat_advanced_cluster_management_for_kubernetes/2.8/html/clusters/cluster_mce_overview#creating-a-cluster-on-premises

https://access.redhat.com/documentation/en-us/red_hat_advanced_cluster_management_for_kubernetes/2.8/html/clusters/cluster_mce_overview#scale-hosts-infrastructure-env is also related as that's effectively the procedure once you have a cluster deployment and infraenv for the imported cluster ( the missing bit now)

The upstream documentation for this is https://github.com/openshift/assisted-service/blob/290cea4b5f5bb10724d455a975e4da83e48ca8ef/docs/hive-integration/import-installed-cluster.md. This is what would need to be added somewhere.