Add Chinese translation & fix zh doc build process

[muscaestar]

This PR introduces:

✅ New Chinese translations for documentation:

• Fully translated recently added English documentation
  • docs/source/zh/examples/web_browser.mdx
  • docs/source/zh/tutorials/inspect_runs.mdx
  • docs/source/zh/tutorials/memory.mdx
  • docs/source/zh/guided_tour.mdx
• Updated table of contents

🔧 Build process fixes:

• Resolved doc-builder build smolagents docs/source/zh/ --build_dir ~/tmp/test-build failure caused by missing Chinese documentation paths

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.

[albertvillanova]

Thank you!