Ahodges/documentation/doc764

@WatsonEmily , please distribute for PM review for usability by our audience.
@jhelbert , @stroilova , @shnayder , @rocha  please review for accuracy, completeness, and level of detail, particularly wrt data czars who will need to revise scripts for post-download processing.
@mhoeber , @srpearce please copy edit.
OK, I didn't know when the weekly file would be removed. Since October is still two months away, and features sometimes slip, it would be _nice_ to provide some instructions here, but I can understand that other priorities take precedence.

It looks like I did mean "wrapped" (though I think of "wrapped" differently). Thanks for the tip about formatting.