Order of the material

[ivelasq]

Starting a discussion on the order of the material in the book.

A response from the Spring Seminar:

• [1] I get why you're not talking about the survey design object in detail right now, but I think it would be helpful to give a little more conceptual information now about how complex data analysis differs from SRS analysis and why the design object is necessary, just so folks who don't have much experience with complex data analysis can have that background.

[ivelasq]

Covered in setup chapter