fix documentation for user skip confirmation

closes PS-1465

Change-Id: I0fe99ad4f42ed604a033d1901ec029ede3f7d628
Reviewed-on: https://gerrit.instructure.com/33830
Reviewed-by: Brandon Broschinsky <brandonbr@instructure.com>
Product-Review: Adam Phillipps <adam@instructure.com>
QA-Review: Adam Phillipps <adam@instructure.com>
Reviewed-by: Adam Phillipps <adam@instructure.com>
Tested-by: Jake Sorce <jake@instructure.com>