Fix typo in clone URL

README.md

@@ -46,7 +46,7 @@ The code will automatically normalize your audio (i.e., resampling + mono channe
 First of all, please install the **development** version of SpeechBrain with the following command:
 
 ```
-pip install git+https://github.com/speechbrain/speechbrain.git@$develop
+pip install git+https://github.com/speechbrain/speechbrain.git@develop
 ```
 
 Please notice that we encourage you to read our tutorials and learn more about