add i18n feat && Add partial translation

package.json

@@ -71,6 +71,8 @@
     "express": "^4.18.2",
     "fuse.js": "^7.0.0",
     "gray-matter": "^4.0.3",
+    "i18next": "^25.7.4",
+    "i18next-browser-languagedetector": "^8.2.0",
     "jsonwebtoken": "^9.0.2",
     "katex": "^0.16.25",
     "lucide-react": "^0.515.0",
@@ -81,6 +83,7 @@
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
     "react-dropzone": "^14.2.3",
+    "react-i18next": "^16.5.3",
     "react-markdown": "^10.1.0",
     "react-router-dom": "^6.8.1",
     "rehype-katex": "^7.0.1",