fix up typo (#57)

CONTRIBUTING.md

@@ -22,14 +22,14 @@ To set up a working development environment, just fork the project git repositor
 
 ### Fork the repository
 
-you need to fork the [repository](https://github.com/langgenius/langgenius-gateway).
+you need to fork the [repository](https://github.com/langgenius/dify).
 
 ### Clone the repo
 
 Clone your GitHub forked repository:
 
 ```
-git clone git@github.com:<github_username>/langgenius-gateway.git
+git clone git@github.com:<github_username>/dify.git
 ```
 
 ### Install backend