update install.sh to use a python virtual environment

[november781]

currently the automatic install script on Linux runs pip install with the requirements file in the default system environment unless the user activates a virtual environment before executing install.sh.

I personally think it would be better practice to have the install script create a virtual environment for the user and activate it before calling pip install to avoid module conflicts with other system resources and other projects.

virtual enviroments are built into python 3.4 and above with the venv command and since the project seems to be targeting 3.8+ at least, it shouldn't be an issue.

creating a virtual environment can be done with python -m venv {environment_name} and can be activated with source {environment_name}/bin/activate before running pip install in the script and that should cover anyone running install.sh

by using a virtual environment you could drop the --user flag from pip install