Update AI principles and guidelines.

[edonehoo]

Iterate on #4545 (comment) to incorporate additional suggestions from Kri:

• Could we offer a downloadable PDF/file instead of web-based checklist?
• Adjust: "Value and need: AI is aligned with user needs and values and will be continuously refined based on user feedback and ethical considerations."
  • it's a little generic. "Maybe a better checklist item is that the user need and value proposition has been documented for every AI product? Kind of like how in UXD we want to always have a problem statement that we're solving for before we start a project."
• When discussing "determine if AI adds value":
  • We aren't differentiating between gen AI and other AI. Perhaps offer guidance that distinguishes potential use cases for each, encouraging exploration? While gen AI still has accuracy issues, other structured types of AI may be better for tasks with lower risk tolerance, for ex.