feat: 添加download路由用于展示文档信息

- 添加/download/documentID路由用于文档下载
- server端添加文档元数据获取与下载API
- 将app中的types移至shared，与server共享

i18n/locales/en.json

@@ -34,6 +34,7 @@
     "support": "Support",
     "about-us": "About Us",
     "contact-info": "Contact Info",
+    "downloads": "Downloads",
     "faq": "FAQ",
     "documents": "Documents",
     "calculator": "Calculator"

i18n/locales/zh.json

@@ -34,6 +34,7 @@
     "support": "服务支持",
     "about-us": "关于我们",
     "contact-info": "联系信息",
+    "downloads": "文件下载",
     "faq": "常见问题",
     "documents": "文档资料",
     "calculator": "纸管计算工具"