* Adding manage roles page to docs * Adding instructions for assigning principals and grants to a role * adding terraform to assign principles example and assign grants example * docs: add role clickthroughs and step-by-step instructions * Removing old manage role screenshots for admin workflow Co-authored-by: Pete Pacent <ppacent@hashicorp.com> Co-authored-by: Randall Morey <randall@randallmorey.com>