Update docs/guides/deployment-scenarios/sso-quickstart.md,...

Package Merge Request

Package Changes

Formatting/editing/grammatical changes made to multiple Guides pages, including Deployment scenario page: SSO Quick-start page and Back-up and Restore pages: Gitlab Back-up Restore and Nexus migration pages.

Package MR

(Link to Package MR here)

For Issue

Closes (link to issue here)

Upgrade Notices

(Include any relevant notes about upgrades here or write "N/A" if there are none)