Lesson 18 creating arrays should say 'unroll' not 'unwrap'

[jman904]

On lesson 18 "creating arrays", about 1/3 of the way down the page loop unrolling is used to facilitate loop understanding, but referred to as "unwrap" which is non-standard terminology for this technique. The instance of "unwrap" in the text should be replaced with "unroll" instead.

https://en.wikipedia.org/wiki/Loop_unrolling