Add steps 6 & 7 in installing from source

Author: UnsignedArduino

README.md

@@ -89,3 +89,26 @@ Due to how new this project is, there are no binaries currently.
  ```commandline
  . .. assets default_circuitpython_hierarchy .git .gitignore gui.py gui_tools main.py project_tools README.md requirements.txt
  ```
+
+6. If you are going to use a [virtual environment](https://docs.python.org/3/library/venv.html), run the following 
+ commands:
+ 1. Windows:
+ ```commandline
+ python -m venv .venv
+ ".venv/Scripts/activate.bat"
+ ```
+ 2. macOS and Linux:
+ ```commandline
+ python3 -m venv .venv
+ source .venv/bin/activate
+ ```
+
+7. Install the packages:
+ 1. Windows:
+ ```commandline
+ pip install -r requirements.txt
+ ```
+ 2. macOS and Linux:
+ ```commandline
+ pip3 install -r requirements.txt
+ ```