更新文件结构，统一文档格式

backend/README.md

@@ -38,7 +38,7 @@ cp .env.example .env
 
 2. 编辑 `.env` 文件，配置你的环境变量：
 ```env
-MONGODB_URI=mongodb://localhost:27017/jiebanke
+MONGODB_URI=mongodb://mongodb.jiebanke.com:27017/jiebanke
 JWT_SECRET=your-super-secret-jwt-key
 ```
 
@@ -81,7 +81,7 @@ Content-Type: application/json
   "username": "testuser",
   "password": "password123",
   "nickname": "测试用户",
-  "email": "test@example.com",
+  "email": "test@jiebanke.com",
   "phone": "13800138000"
 }
 ```