Update get-started docs on accessing AWS
Update get-started docs on accessing AWS

Recommend using the least privileged role available.

I think readers will be able to work out to replace integration with
staging / production, so they don't need that pointing out explicitly.

alphagov/govuk-developer-docs,alphagov/govuk-developer-docs,alphagov/govuk-developer-docs,alphagov/govuk-developer-docs