Move packageRules into own page in the docs

[HonkingGoose]

Describe the proposed change(s).

Blocked by:

• Sort packageRules in docs, validate with tests #29703

Todos:

• Split packageRules content off to a new page (docs/usage/package-rules.md or whatever name is best).
• Add short and simple introductory text to the page
• Update the "check packageRules are in correct order" test so it checks the new file.
• Confirm packageRules items are in the correct order.
• Update all the old links that point to packageRules items, there will be a lot of links! I think we have docs tests for broken links already, that will help to update all the links.
• Merge PR, and enjoy new page.