code implies comprehension when it isn't

This idiom section implies that `for...   body` is also a comprehension like `body for...`. I think it could be more clear that it's running a more tradition for loop with a body and the only value returned is the result of the last body and not all bodies.

https://github.com/arcturo/library/blob/6494178e82c5c479dcb58ff3857f5bbcdc91c648/coffeescript/04_idioms.html#L105,L113