Support Mermaid swimlane diagrams by upgrading to Mermaid 11.16+

Outline currently uses Mermaid 11.15.0, while native swimlane diagrams were
introduced in Mermaid 11.16.0.

Using the documented syntax:



results in:

Invalid or unsupported diagram

Expected behavior:
Outline should render Mermaid swimlane diagrams supported by Mermaid 11.16+.

Relevant documentation:


Related but already closed:
#6798 — Not all mermaid diagrams available
#7964 — Mermaid v11 upgrade