docs: document ERROR notices

[lionel-nj]

closes #849

Summary:

This PR provides additional documentation for notices.

TODOs

• document ERROR notices
• document WARNING notices
• document INFO notices
• document system errors
• add reference to NOTICES.md in RULES.md and NEW_RULES.md

Please make sure these boxes are checked before submitting your pull request - thanks!

• [ ] Run the unit tests with gradle test to make sure you didn't break anything
• Format the title like "feat: [new feature short description]". Title must follow the Conventional Commit Specification(https://www.conventionalcommits.org/en/v1.0.0/).
• Linked all relevant issues
• [ ] Include screenshot(s) showing how this pull request works and fixes the issue(s)

[maximearmstrong]

Great job! I think only one thing is missing: the notice code for each notices. In the reports, the only way to find a notice is by its code, so I think we should add it here.

[maximearmstrong]

LGTM :)