All options include both a class diagram and a workflow/activity diagram. I recommend Option A.
Core classes + important helpers + clean workflow
Keep `PROJECT_UML.md`, correct details from the code, and make the diagrams readable for README/docs use.
Small, teaching-oriented diagram
Focus only on the notebook-facing API and the main docking sequence.
More diagrams, more relationships
Add class, workflow, module/dependency, and artifact-output diagrams.