Update README.md

Author: MichaelClerx

README.md

@@ -19,13 +19,15 @@ cd pcpostprocess
 Create and activate a virtual environment.
 
 ```sh
-python3 -m venv .venv && source .venv/bin/activate
+python3 -m venv .venv
+source .venv/bin/activate
 ```
 
 Then install the package with `pip`.
 
 ```sh
-python3 -m pip install --upgrade pip && python3 -m pip install -e .'[test]'
+python3 -m pip install --upgrade pip
+python3 -m pip install -e .'[test]'
 ```
 
 To run the tests you must first download some test data.