feat: add breaking changes section for grouped release notes

[Copilot]

Breaking Changes Implementation - Merge Complete

Successfully merged with main branch and resolved all conflicts.

Changes Merged from Main

• CI/CD workflows for linting and testing
• New Contributors section preservation feature
• Extended .gitignore patterns
• Contributing documentation

Conflict Resolutions

1. .gitignore - Combined ignore patterns from both branches
2. tests/test_release_notes.py - Preserved all test cases from both branches (11 total tests now)
3. pretty_release_notes/models/release_notes.py - Auto-merged successfully with both breaking changes and new contributors features

Test Status

✅ All 11 tests in test_release_notes.py passing
✅ Breaking changes feature working correctly
✅ New contributors feature preserved and working
✅ Features work together harmoniously

Original prompt

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This section details on the original issue you should resolve

<issue_title>Add section for breaking changes</issue_title>
<issue_description>Breaking conventional commits, e.g `fix!: change how things work" (with an exclamation mark) currently get grouped under "Other Changes".

They should ideally be grouped as "Breaking Changes".</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Add section for breaking changes #3

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[barredterra]

@copilot resolve merge conflicts

[Copilot]

@copilot resolve merge conflicts

Merge conflicts resolved in commit c24e285.

Resolved conflicts:

• .gitignore - Combined ignore patterns from both branches
• tests/test_release_notes.py - Preserved all 11 test functions (3 breaking changes tests + 2 new contributors tests + 6 existing)
• pretty_release_notes/models/release_notes.py - Auto-merged successfully

All tests passing ✅