Create an internal docs / wiki site

[jacobsmith928]

As Datum grows, we need an internal "wiki" or docs site to capture operational playbooks, ways of working, etc. We should leverage our existing investment in Astro / Starlight for our public docs and handbook to create this site, allowing for cohesion and ease of maintenance.

• It should be hosted on a 3rd party (GCP) for continuity during outages
• It should be protected by Datum SSO for internal access only
• The content should be driven off of a private repo (consult with @drewr on this)

[felixwidjaja]

Or, not leverage the existing, but look to real wiki solution. Primary candidate: https://js.wiki/ (passed the requirements)
Honorable mention: https://www.bookstackapp.com/