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. 

Note: Doc team updates the current version and the two previous versions (n-2). For earlier versions, we will address only high-priority, customer-reported issues for releases in support.

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 3:

 - Use the Customer Portal: https://access.redhat.com/documentation/en-us/red_hat_advanced_cluster_management_for_kubernetes/2.6

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

It is a new component, so there is nothing in the ACM documentation to base it on.

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

Provide info for the following steps:

1. - [ X ] Mandatory Choose the documentation release (Published releases are refreshed ~weekly after publication). 
     
      - [ ] ACM 2.4
      - [ ] ACM 2.5
      - [ ] ACM 2.6
      - [ ]ACM 2.7 (upcoming release)
      - [ X ]ACM 2.8 (upcoming release)

      - [ ] MCE 2.0
      - [ ] MCE 2.1 
      - [ ] MCE 2.2 (upcoming release)

(please note its an ACM only component, will not be part of MCE)
   

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 bugs: What is the diff? Clearly define what the problem is, what the change is, and link to the current documentation:

4. - [ X ] Mandatory for GA content:

(please note this is going to be TP, not GA)
            
       - [ X ] Add steps and/or other important conceptual information here: 
Upstream page with documentation: https://github.com/stolostron/cluster-templates-operator       

Cluster as a Service (CaaS) is a  new operator which allows self service cluster creation to non privileged users. It introduces a set of guardrails to make sure the end user will only be allowed to create a very specific cluster and only a specific amount of them.

The whole flow is based around gitops and ACM policies.

           
       - [ X ] Add Required access level for the user to complete the task here:
for the end user: https://github.com/stolostron/cluster-templates-operator/blob/main/docs/dev-permissions.md

for the admin user: full admin permissions so that they can install the operator, configure argo, create namespaces, create quotas.

       - [ X ] Add verification at the end of the task, how does the user verify success (a command to run or a result to see?)
     The full flow defined in https://github.com/stolostron/cluster-templates-operator/blob/main/docs/quick-start.md

The last verification at the very end of the flow would be to create an instance of the ClusterTemplateInstance and make sure the cluster actually deployed.
     
       - [ X ] Add link to dev story here:

backend: https://issues.redhat.com/browse/MGMT-11658

UI: https://issues.redhat.com/browse/MGMT-11657

   - Errata release note version, this is NOT for regular refreshes: 
      (published with Errata release)
  
      - [ ] ACM 2.4.x
      - [ ] ACM 2.5.x
      - [ ] ACM 2.6.x

      - [ ] MCE 2.0.x

      - [ ] MCE 2.1.x