Reader permission needed in the docs

[David Leiva]

Previously we use to mention that Reader permissions needs to be added in Azure because its needed to access workspaces apis, right now is not referenced

[Arun Pamulapati]

@marco-ferraro-db, can you update the docs? Please see this doc for the details including the screenshot : https://github.com/databricks-industry-solutions/security-analysis-tool/blob/main/docs/deprecated_old_setup.md#authentication-information