[Docs]Update Chinese document for speed benchmark

[HanaRo]

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Motivation

Lack of Chinese document for benchmark.md, from issue #1361

Modification

Update Chinese document for benchmark.md

Checklist

1. Pre-commit or other linting tools are used to fix the potential lint issues.
2. The modification is covered by complete unit tests. If not, please add more unit test to ensure the correctness.
3. If the modification has potential influence on downstream projects, this PR should be tested with downstream projects.
4. The documentation has been modified accordingly, like docstring or example tutorials.

[CLAassistant]

All committers have signed the CLA.