docs: add VitePress documentation site

- Add docs directory with VitePress configuration
- Add GitHub Actions workflow for docs build and deploy
- Support bilingual (English/Chinese) documentation
- Include search, custom theme, and responsive design

docs/.gitignore

@@ -0,0 +1,43 @@
+# Dependencies
+node_modules/
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+
+# Build outputs
+.vitepress/dist/
+.vitepress/cache/
+docs/.vitepress/dist/
+docs/.vitepress/cache/
+dist/
+public/search-index.*.json
+
+# Editor directories and files
+.vscode/
+.idea/
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.sw?
+.DS_Store
+
+# Temporary files
+*.tmp
+*.temp
+.cache/
+
+# Logs
+logs/
+*.log
+
+# Environment
+.env
+.env.local
+.env.*.local
+
+# OS
+.DS_Store
+Thumbs.db
+.ace-tool/