[facelessuser]

Rule of 3: an ambiguous delimiter cannot pair with an open delimiter if the sum of the original lengths is a multiple of 3 (unless both are multiples of 3).

3 existing test were changed. These matched the results of other CommonMark parsers but not the official CommonMark implementation. These other parsers missed a subtle interpretation of the rule of 3 that the official implementation applies.

AI was used to pin down where we deviated and generate the tests to capture where we deviated.
It particualry was particularly useful to identify why some CommonMark parsers don't match the
official one with certain applications of the "rule-of-3".

Fixes #1690

Description

AI Assistance Disclosure

• No AI tools were used in preparing this PR.

• AI tools were used and I have disclosed which ones, and have fully reviewed and verified their output.

  AI tools were use to assist with the following:

  • Code
  • Code Comments
  • Documentation
  • Changelog Entry
  • Commit Message
  • The Description Above
  • Other: To pin down where we deviated and generate tests that we should match.

Checklist

• This PR follows the contribution guidelines.
• The code follows the Code Style Guide.
• The commit message follows the Commit Message Style Guide.
• I have added or updated relevant docs, including release notes if applicable which follow the Documentation Style Guide.
• I have added or updated relevant tests.
• I have not requested, and will not request, an automated AI review for this PR.