translation: Update chapter_hashing/index.md

[K3v123]

refined some sentences to make it sound more fluent.

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[krahets]

Thanks for the PR!

Randomly assign ['@yuelinxin' '@Phoenix0415'] to review the pull request #1069

[yuelinxin]

Good work, thanks for the PR!

[Phoenix0415]

Thanks for the PR! Good job!