[Feature] Improve Chinese translation and add search-related Chinese translations

[imjokey]

I confirm:

• I have read the Hugo Clarity theme documentation.
• I have reviewed other issues in this repository, and this feature has not already been requested.

Type of feature (check all that apply)

• Site functionality
• Design (styling)
• Site performance
• Accessibility
• Translations and internationalization (i18n)
• Code improvements
• Other (please describe below)

Describe the feature

Some Chinese translation items are missing in existing projects, and Chinese translations for search-related functions are missing, I hope to improve it.

Preferred solution

I can help to improve it.

Alternatives

No response

Additional Context

No response