docs: update and complete Chinese translation (README_ZH.md)

[JasonYeYuhe]

Description

This Pull Request provides a comprehensive update and completion of the Chinese localized README (docs/README_ZH.md).

Motivation
The existing README_ZH.md was significantly outdated and incomplete (approx. 7.5KB compared to the English README's 14KB). As Open Interpreter gains traction within the global developer community, an accurate, structurally equivalent, and high-quality Chinese translation is essential to lower the barrier of entry for Chinese-speaking users.

Changes Made

• Fully translated the latest version of the main README.md into Chinese.
• Ensured strict structural parity with the English README (including all headings, code blocks, configuration snippets, and links).
• Maintained standard technical terminology for clarity and accuracy.
• Retained all existing badges and formatting according to the project's original styling.
• (Note: The language switcher in the main README.md was already pointing to docs/README_ZH.md, so no changes to the main README.md were necessary.)

Validation

• Validated markdown syntax to ensure correct rendering.
• Manually checked parity section by section against the current main branch.

Please let me know if there are any specific formatting adjustments or terminology changes you would prefer. Thank you for building such an incredible project!