[Bug] Cannot search in Chinese string

[Jockeyvb]

Describe the bug
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To Reproduce
Steps to reproduce the behavior:

1. Searchbox Cannot search in Chinese string

Expected behavior
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Context (please complete the following information):

• OS: Windows
• Docfx version: [e.g. 2.78.5+fafdcd5ddacdb756bd5c4b84f2f07c18292e4821]

Additional context
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[filzrev]

It looks like currently Chinese(zh) language is not supported on existing lunr.js based implementation.
https://github.com/dotnet/docfx/blame/main/templates/modern/src/search-worker.ts#L110-L111