Add comprehensive multi-language documentation guide

[Copilot]

The repository already supports multi-language documentation (English/Chinese) via Fumadocs i18n, but lacked documentation explaining how to build and maintain it.

Changes

• New documentation pages (content/docs/i18n-guide.{en,zh-CN}.mdx):

  • Configuration setup: i18n config, UI translations, source loader, app layout
  • Content creation: file naming conventions ({filename}.{lang}.mdx), frontmatter structure, navigation via meta.{lang}.json
  • Adding new languages: complete workflow with code examples
  • Troubleshooting: common issues (404s, missing navigation, language switcher)
  • Repository structure reference

• Updated navigation (meta.{en,zh-CN}.json): Added guide to sidebar

• Enhanced README: Project overview, getting started, link to i18n guide

Example Structure

content/docs/
├── index.en.mdx          # English version
├── index.zh-CN.mdx       # Chinese version
├── meta.en.json          # English navigation
└── meta.zh-CN.json       # Chinese navigation

Preview

The guide is accessible at /en/docs/i18n-guide and /zh-CN/docs/i18n-guide:

Original prompt

如何构建多语言的文档，

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💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

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Project	Deployment	Review	Updated (UTC)
docs	Ready	Preview, Comment	Jan 15, 2026 10:19am

[huangyiirene]

@copilot 我有一套主的英文文档，是我来维护的其他国家语言的文档，我希望AI自动翻译。我希望做搜索引擎优化每一套文档应该在各自的语言路径下。