add screenshots floder

README.md

@@ -105,7 +105,7 @@ npm run dev (需先开启mongodb)
 
 ### 部分前台页面
 
-<img src="http://cangdu.org/files/images/elm_msite.png" width="365" height="619"/><img src="http://cangdu.org/files/images/elm_shop.png" width="365" height="619"/>
+<img src="https://github.com/bailicangdu/node-elm/blob/master/screenshots/elm_msite.png" width="365" height="619"/><img src="https://github.com/bailicangdu/node-elm/blob/master/screenshots/elm_shop.png" width="365" height="619"/>
 
 
 ### License