fix the typo contributing.md (#662)

fix contributing.md

Author: naman9271

docs/contributing.md

@@ -71,7 +71,7 @@ git clone https://github.com/USERNAME/AIOD-rest-api.git
 Always make sure to install your dependencies in a local environment, for example with the built in `venv` module:
 
 ```commandline
-python -m pip venv venv
+python -m venv venv
 source venv/bin/activate
 ```