Need to add some instructions for saving and loading you environment to lab content

[rotycenh]

We've got notes in labs 3 and 4 stating we assume they are still running the environments they used during lab 2. Is it possible to add a note at the end of Lab 2 telling readers how to save and load their environment settings to avoid the situation where they've completed lab two, but didn't leave the environment open before starting Lab 3 (or at least a warning telling them to leave the environment open?).

[sonwan2020]

#166