Lint: Prefer cross-references to explicit anchor tags when possible

[michael-wisely-gravwell]

Task

What needs to be done?

Add a some kind of lint rule to complain when it sees <a> tags.

Why is this task needed?

Cross-references are a really useful feature in sphinx:

• Tolerant to restructure
  • If pages move or change (or whatever), cross-references will automatically update, and links will remain intact.
• Error checking
  • If a cross-reference is broken somehow (page is deleted, ref is misspelled), then sphinx/myst will complain about it. The tool will help you find broken links.

Any other comments?

Medium because I think using cross-references can save us some headaches down the road.