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

Provide info for the following steps:

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

      - [ ] MCE 2.0
      - [ ] MCE 2.1 
      - [x] MCE 2.3 (upcoming release)
   

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

Current: https://access.redhat.com/documentation/en-us/red_hat_advanced_cluster_management_for_kubernetes/2.7/html/clusters/cluster_mce_overview#ansible-template-run-cluster-console:~:text=existing%20automation%20template.-,1.5.9.3,-.%C2%A0Creating%20an%20Automation

Mentions you can apply the templates you create to a Cluster-but I couldn't find a place in doc that tells you how to apply it-and this seems like a great spot to have that 411:

"Your Ansible template is configured to run on clusters that specify this template when the designated actions occur."

To apply the template you open the cluster page and select "Update automation template" in a context menu or from the batch dropdown. You can only apply one so you got to make it count! This opens a model that lets you pick the Ansilbe template. If it had none before, now it does.

The purpose of this PR is to add a new menu item "Remove automation template" which lets you remove that template leaving the cluster with none (1-1 = 0)