Bump flatted from 3.2.7 to 3.4.1 in /docs (#3010)

Bumps [flatted](https://github.com/WebReflection/flatted) from 3.2.7 to 3.4.1.
- [Commits](WebReflection/flatted@v3.2.7...v3.4.1)

---
updated-dependencies:
- dependency-name: flatted
  dependency-version: 3.4.1
  dependency-type: indirect
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]