keeping track of issues with data ideas

[hardin47]

Feeling done with adding exercises for V2. But if we are looking for ideas for V3, we might choose to look back to these issues:

Chapter 12 & 16 (one proportion) #292
Chapter 20 (two sample t-test) #258
Chapter 21 (paired t-test) #286

gss issues #406

[hardin47]

The gssr package has now been updated.
see this issue: kjhealy/gssr#10 (comment)