chinese i18n fix (#17190)

* fix: fix dialog some key capitalization

* chore: remove audio duplicate key. (i18next can't use it! maybe need change key name? )

* feat: add chinese missing keys.
fix: fix some keys error

* feat: add chinese readme file

* feat: add system feature pages embeddings i18n keys

* fix: fix audio file keys wrong

web/public/locales/zh-CN/components/input.json

@@ -3,7 +3,7 @@
     "downloadVideo": {
       "label": "下载视频",
       "toast": {
-        "success": "下载成功"
+        "success": "您的回放视频已开始下载。"
       }
     }
   }