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

All is related to this doc:

• https://access.redhat.com/documentation/en-us/red_hat_advanced_cluster_management_for_kubernetes/2.10/html/observability/using-observability#external-metric-query

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.

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

3. - [ ] Mandatory for GA content:
            
       - [ ] Add steps and/or other important conceptual information here: 
       
            
       - [ ] Add Required access level for the user to complete the task here:
       

       - [ ] Add verification at the end of the task, how does the user verify success (a command to run or a result to see?)
     
     
       - [ ] 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:

The whole doc is simply unclear. It does not provide a clear way to achieve the goal.

• Why do I need to do a query (step 2.)? I assume is for testings pruposes?
• Where do I get the ca.key from? (step 3.)
• What are really ingress.crt and ingress.key (step 4.)
• The whole thing miss a lot of context and "why's".
• Missing info about metrics are protected by mTLS. That is essential info for customers configuring an external client.

(based on related Slack discussion)