Update README.md

Author: levelopers

README.md

@@ -7,3 +7,14 @@
 #### api documentation:  [swaggerHub](https://app.swaggerhub.com/apis-docs/levelopers2/Ecommerce/1.0.0)
 
 #### populate data: run  `node ./seed` (make sure you fill up `mongo-config` file with mongodb url)
+
+
+
+<details>
+ <summary>data model</summary>
+ <p>
+   
+![react-native-store relational model diagram](https://user-images.githubusercontent.com/38830527/92665263-1c4cb880-f2d4-11ea-85a4-201c41517123.png)
+   
+</p>
+</details>