fix: Chinese character counting error in overview page (#1845)

[HoshinoSuzumi]

This PR adds Chinese character set for word counting and modify wordCount function

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create-slidev

pnpm add https://pkg.pr.new/slidevjs/slidev/create-slidev@1846

@slidev/client

pnpm add https://pkg.pr.new/slidevjs/slidev/@slidev/client@1846

@slidev/parser

pnpm add https://pkg.pr.new/slidevjs/slidev/@slidev/parser@1846

create-slidev-theme

pnpm add https://pkg.pr.new/slidevjs/slidev/create-slidev-theme@1846

@slidev/cli

pnpm add https://pkg.pr.new/slidevjs/slidev/@slidev/cli@1846

@slidev/types

pnpm add https://pkg.pr.new/slidevjs/slidev/@slidev/types@1846

commit: bb48262