Add documents site (#1767)

* feat: add docs site

- Implemented dynamic routing for MDX documentation pages with language support.
- Created layout components for documentation with a header and footer.
- Added metadata for various documentation sections in English and Chinese.
- Developed initial content for the DeerFlow App and Harness documentation.
- Introduced i18n hooks and translations for English and Chinese languages.
- Enhanced header component to include navigation links for documentation and blog.
- Established a structure for tutorials and reference materials.
- Created a new translations file to manage locale-specific strings.

* feat: enhance documentation structure and content for application and harness sections

* feat: update .gitignore to include .playwright-mcp and remove obsolete Playwright YAML file

* fix(docs): correct punctuation and formatting in documentation files

* feat(docs): remove outdated index.mdx file from documentation

* fix(docs): update documentation links and improve Chinese description in index.mdx

* fix(docs): update title in Chinese for meta information in _meta.ts

frontend/src/content/en/application/_meta.ts

@@ -0,0 +1,27 @@
+import type { MetaRecord } from "nextra";
+
+const meta: MetaRecord = {
+  index: {
+    title: "Overview",
+  },
+  "quick-start": {
+    title: "Quick Start",
+  },
+  "deployment-guide": {
+    title: "Deployment Guide",
+  },
+  configuration: {
+    title: "Configuration",
+  },
+  "workspace-usage": {
+    title: "Workspace Usage",
+  },
+  "agents-and-threads": {
+    title: "Agents and Threads",
+  },
+  "operations-and-troubleshooting": {
+    title: "Operations and Troubleshooting",
+  },
+};
+
+export default meta;

frontend/src/content/en/application/agents-and-threads.mdx

@@ -0,0 +1,3 @@
+# Agents and Threads
+
+TBD

frontend/src/content/en/application/configuration.mdx

@@ -0,0 +1,3 @@
+# Configuration
+
+TBD

frontend/src/content/en/application/deployment-guide.mdx

@@ -0,0 +1,3 @@
+# Deployment Guide
+
+TBD

frontend/src/content/en/application/index.mdx

@@ -0,0 +1,3 @@
+# DeerFlow App
+
+TBD

frontend/src/content/en/application/operations-and-troubleshooting.mdx

@@ -0,0 +1,3 @@
+# Operations and Troubleshooting
+
+TBD

frontend/src/content/en/application/quick-start.mdx

@@ -0,0 +1,3 @@
+# Quick Start
+
+TBD

frontend/src/content/en/application/workspace-usage.mdx

@@ -0,0 +1,3 @@
+# Workspace Usage
+
+TBD