Update SaaS Basics Module - Add Access Request Info for Sentry

While doing this module, I found I did not have access to Sentry.

I discovered that an Access Request issue must be opened to obtain this access, so I've added the information on this process to the appropriate step in the module.

to-do: revisit whether this should be a baseline entitlement for support engineers or not - currently, it is not, according to the Tech Stack.