Found broken `/preparation-for-study/app.comflowy.com` link. Please fix!

この issue には説明がありません。

Find the broken link '/preparation-for-study/app.comflowy.com' in the repository's documentation files, likely in an MDX file. Search for the link text or URL to locate the file. Correct the link to the intended destination, which may involve checking other documentation for the correct path. Verify the fix by building or previewing the documentation locally.

索引モデルが issue の本文から書いたものです。