fixing out of date guidance

[earth2marsh]

Updated contributing guidelines to clarify the process for editing AEP rules and submitting PRs. Removes out-of-date information about the site generator and points to our dedicated repo.

🍱 Types of changes

What types of changes does your code introduce to AEP? Put an x in the boxes that apply

• [ ] Enhancement
• [ ] New proposal
• [ ] Migrated from google.aip.dev
• [ ] Chore / Quick Fix

📋 Your checklist for this pull request

Please review the AEP Style and Guidance for contributing to this repository.

General

• [ ] Basic Guidance is met.
• [ ] Ensure that your PR references AEPs correctly.
• [ ] My code has been formatted (run make lint)

💝 Thank you!

[earth2marsh]

@rambleraptor DYK if the formatting guidance at the end of this document still applies? If not, I'll take it out as well.

[toumorokoshi]

please make sure lint passed before merging!

[rambleraptor]

@earth2marsh can you run npm run lint to fix the linter issues? You should be free to merge after that.