Update instructions for setting up Ratify on Azure

[shahramk64]

The existing doc on setting up Ratify with Azure has a few issues:
1- The Yaml config files that are presented to set up AKS are not provided with the correct indentations
2- Some steps are not required or not relevant. For example, Register the 'EnableWorkloadIdentityPreview' feature flag is not relevant and should be removed.
3- There are a few typos: keymanagementprovider-akv is used as a name inside a yaml config file, but it's referenced in the subsequent commands in CamelCase format.