feat: Add metadata and descriptions to various documentation pages in Chinese

- Added titles and descriptions to workspace usage, configuration, customization, design principles, installation, integration guide, lead agent, MCP integration, memory system, middleware, quick start, sandbox, skills, subagents, and tools documentation.
- Removed outdated API/Gateway reference and concepts glossary pages.
- Updated configuration reference to reflect current structure and removed unnecessary sections.
- Introduced new model provider documentation for Ark and updated the index page for model providers.
- Enhanced tutorials with titles and descriptions for better clarity and navigation.

deer-flow.code-workspace

@@ -5,7 +5,7 @@
     }
   ],
   "settings": {
-    "typescript.tsdk": "frontend/node_modules/typescript/lib",
+    "js/ts.tsdk.path": "frontend/node_modules/typescript/lib",
     "python-envs.pythonProjects": [
       {
         "path": "backend",
@@ -44,4 +44,4 @@
       }
     ]
   }
-}
+}