Add pages for layout roots

Currently, there is no information that explains Layout area roots.
This areas can be used to inform user of their meaning and usage.
Also, they can present useful links that improve user flow and discovery.

Specs

• Create a page with a url for each root
  • Each will have a help text (not in the scope for this ticket)
  • Have navigation action to modeler configuration on some:
    • Local type: Document Type configuration in modeler
    • Workflow: Workflow configuration in modeler
    • Built-in Types: ?
    • Page Provider: Page Provider in modeler

Links for documentation

• Doc types
• Workflows
• Page Providers

Links for university

• Doc type & Workflows
• Page providers - in progress