How to setup a virtual environment with Anaconda (and/or venv)

[jiqicn]

I found that it could be nice to add the content of creating a virtual environment to the "Summary and Setup" session. There are several reasons for doing that:

• It's a very useful concept.
• I guess we don't want to ruin the system-level Python installation or the base env of Anaconda on students' computers.
• Anaconda is introduced along the course and it can be easily introduced together with the Anaconda setup.