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

[imjokey]

I confirm:

• [X] I have read the Hugo Clarity theme documentation.
• [X] 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
• [X] Accessibility
• [X] 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