Changed .env to .venv in README.rst

Author: evaherrada

README.rst

@@ -49,8 +49,8 @@ To install in a virtual environment in your current project:
 .. code-block:: shell
 
  mkdir project-name && cd project-name
- python3 -m venv .env
- source .env/bin/activate
+ python3 -m venv .venv
+ source .venv/bin/activate
  pip3 install adafruit-circuitpython-busdevice
 
 Usage Example