Merge pull request #4150 from nicgirault/add-express-sequelize-crud

add express-sequelize-crud to the list of data provider backends

docs/DataProviders.md

@@ -66,6 +66,7 @@ The react-admin project includes 4 Data Providers:
 Developers from the react-admin community have open-sourced Data Providers for many more backends:
 
 * **[Django Rest Framework](https://www.django-rest-framework.org/)**: [synaptic-cl/ra-data-drf](https://github.com/synaptic-cl/ra-data-drf)
+* **[Express & Sequelize](https://github.com/lalalilo/express-sequelize-crud)**: [express-sequelize-crud](https://github.com/lalalilo/express-sequelize-crud)
 * **[Feathersjs](http://www.feathersjs.com/)**: [josx/ra-data-feathers](https://github.com/josx/ra-data-feathers)
 * **[Firebase](https://firebase.google.com/docs/database)**: [aymendhaya/ra-data-firebase-client](https://github.com/aymendhaya/ra-data-firebase-client).
 * **[Firestore](https://firebase.google.com/docs/firestore)**: [rafalzawadzki/ra-data-firestore-client](https://github.com/rafalzawadzki/ra-data-firestore-client).