docs: document not operator

[jd]

Fixes MRGFY-4653

[mergify]

Merge Protections

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🟢 Changelog requirements

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• any of:
  • -title ~= ^feat
  • label = need changelog
  • label = skip changelog

🟢 Enforce conventional commit

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Make sure that we follow https://www.conventionalcommits.org/en/v1.0.0/

• title ~= ^(fix|feat|docs|style|refactor|perf|test|build|ci|chore|revert)(?:\(.+\))?:

🟢 🔎 Reviews

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• #changes-requested-reviews-by = 0
• #review-requested = 0
• #review-threads-unresolved = 0