All of Docsy's other optional features are opt-in. The same should be true of draw.io.

• Support was added via Add support for editing diagrams.net diagrams #529

Tasks:

• Remove setting from Docsy config:
  

  docsy/config.yaml

  Lines 9 to 10 in 215f680

  	drawio:
  	enable: true

• Add setting to UG config
• Update the docs to let users know how to opt-in:
  https://docsy.dev/docs/adding-content/diagrams-and-formulae/#diagrams-with-diagramsnet

/cc @LisaFC @gwatts