Suggest / Add instructor notes for Episode 4: Faceting and filtering

[ostephens]

Following the transition to the new Workbench, instructor notes can be integrated into episodes/lessons. This issue is for

Episode 4: Faceting and filtering

Some notes could be copied from the existing notes, but this is also a good opportunity to make sure we have all appropriate instructor notes in place so we can use this issue for suggestions for any additional notes that should also be added.

Read for details on how to format instructor notes.

[ostephens]

This episode is the first part of the lesson where the participant makes a substantive change to the data in the project, and so the instructor may wish to mention the Undo/Redo functionality at this point, even though it is only covered in detail in episode 9. Mentioning it here as something to be looked at later will introduce this powerful aspect of OR and reassure participants that they can always undo any changes they make to the data