quick start, GHEC, license edits

Updates in preparation for the NMFS GHEC roll-out

Some minor edits

• Use Guidelines and Best Practices instead of SOP throughout
• Add a Backups section.

Add references and changed the intro to give better context

• Add reference links
• Discuss the center specific SOPs

v3.1 Converted to Quarto

This is essentially version 3.0 but the gitleaks sections was removed since gitleaks is now extremely expensive.