Hi Team, Few section in 1.3. Enabling the Observability service

was not clear to customer and was creating issue, hence we have updated the document with details.

• Modified [Prerequisites] section (https://docs.redhat.com/en/documentation/red_hat_advanced_cluster_management_for_kubernetes/2.12/html-single/observability/index#prerequisites-observability)
  Before : You must define a storage class in the MultiClusterObservability custom resource, if there is no default storage class specified.
  After : - You must specify the storageConfig.storageClass field in the MultiClusterObservability custom resource if you do not want to use the platform's default StorageClass.

• Modified 1.3.2.3. Creating the MultiClusterObservability custom resource

Added:

Note: By default if you do not define the storageConfig.storageClass field in the MultiClusterObservability custom resource, platforms default StorageClass will be populated in the storageConfig section of MultiClusterObservability. For example for AWS default storageClass will be gp2. You can verify default storageClass using below command:

$ oc get storageClass
NAME                PROVISIONER       RECLAIMPOLICY   VOLUMEBINDINGMODE      ALLOWVOLUMEEXPANSION   AGE
gp2-csi             ebs.csi.aws.com   Delete          WaitForFirstConsumer   true                   151m
gp3-csi (default)   ebs.csi.aws.com   Delete          WaitForFirstConsumer   true                   151m 

•   Also Added $, as it ** was missing in front of all the commands.
  1. - [ ] Mandatory: Add the required version to the RHACM 2.11 + field.

2. - [ ] Mandatory: Choose the type of documentation change or review.

•  We need to update to an existing topic

• [ ] We need to add a new document to an existing section

• [ ] We need a whole new section; this is a function not
  documented before and doesn't belong in any current section

• [ ] We need an Operator Advisory review and approval

• [ ] We need a z-Stream (Errata) Advisory and Release note for
  MCE and/or ACM

3. - [ ] Mandatory: Find the link to where the documentation update
should go and add it to the recommended changes. You can either use the
published doc or the staged repo for this step:

Note: As the feature and doc is understood, this recommendation may
change. If this is new documentation, link to the section where you think
it should be placed.

[ ] Created a PR https://github.com/stolostron/rhacm-docs/pull/7974 

Customer Portal published version

https://docs.redhat.com/en/documentation/red_hat_advanced_cluster_management_for_kubernetes/2.12

Doc staged repo within the ACM Workspace:
https://github.com/stolostron/rhacm-docs

4. - [ ] Mandatory for GA content:

• [ ] Add steps, the diff, known issue, and/or other important
  conceptual information in the following space:

• [ ] *Add Required access level *(example, *Cluster
  Administrator*) for the user to complete the task:

• [ ] 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:

5. - [ ] Mandatory for bugs: What is the diff? Clearly define what the
problem is, what the change is, and link to the current documentation. Only
use this for a documentation bug.'

Addition details: PR has been created for https://github.com/stolostron/rhacm-docs/pull/7974#issuecomment-2984497103