Replace cluster with resource group

[rburrs]

cluster is referenced where it should be resource group

[learn-build-service-prod[bot]]

Learn Build status updates of commit 96bbeee:

:white_check_mark: Validation status: passed

File	Status	Preview URL	Details
articles/aks/faq.yml	:white_check_mark:Succeeded

For more details, please refer to the build report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel

[prmerger-automator[bot]]

PRMerger Results

Issue	Description
Yaml File(s)	This PR includes changes to .yml file(s) owned by another author.

[schaffererin]

assign:schaffererin

[schaffererin]

Hi, @rburrs! Thank you for your contribution to the AKS documentation. I reviewed and approved the change and will now sign off on the PR. :)

sign-off

[prmerger-automator[bot]]

Invalid command: '#sign-off'. Only the assigned author of one or more file in this PR can sign off. @