Ahodges/documentation/doc608

@gwprice , @jimabramson , @marcotuts , @lou-wang , @explorerleslie , @WatsonEmily  please check accuracy and completeness (note the files have different audiences, staff vs. students).
@mhoeber @srpearce please copy edit.
No bold for "check mark" (unless it's **check mark** icon)

Suggest "Click the check mark in the upper right corner of the response" (or "that you can see in the upper right...")