8.3 "Lists" are referred to but were never introduced

[debbieyuster]

Section 8.3 refers to datatype "list" (in the context of grouping a table by a list of columns), but lists were not previously introduced as a datatype. They are not explained in 8.3 and no background is given.

[jwaterman]

I got around this in my class by changing my examples to use make_array(), which works fine with the table.groups() method. The text is also inconsistent with using lists in the table.group() method. The documentation states it should take a column or label, but this chapter has examples that pass in a list to the table.group() method, which works, but the datascience reference suggests it should be using table.groups() method instead.