Content Management System for Documentation with external Authentication

Question

I need a CMS for online documentation for our SaaS Product.

• Markdown or similar (simple) formatting
• Images must be embeddable
• Structure for the different documents
• Version History / Change Tracking
• Cloud or on premise
• External authentication by our own identity provider (JWT o OAuth)
• Role based content and anonymous accessible parts.
• Public accessible (https://docs.company.tld)