🐛 Bug: Additional h2s are dropped from README.md during transition

[JoshuaKGoldberg]

Bug Report Checklist

• I have tried restarting my IDE and the issue persists.
• I have pulled the latest main branch of the repository.
• I have searched for related issues and found none that matched my issue.

Expected

Running npx create-typescript-app in an existing repo shouldn't remove any custom README.md content.

Actual

As seen in https://github.com/JoshuaKGoldberg/text-table-fast/pull/362/files#diff-b335630551682c19a781afebcf4d07bf978fb1f8ac04c6bf87428ed5106870f5L181, an ## Acknowledgements section was removed.

Additional Info

🎁

[github-actions]

🎉 This is included in version v2.22.1 🎉

The release is available on:

• GitHub releases
• npm package (@latest dist-tag)

Cheers! 📦🚀