simple-linked-list: clarify vector order

exercises/practice/simple-linked-list/src/lib.rs

@@ -49,13 +49,13 @@ impl<T> FromIterator<T> for SimpleLinkedList<T> {
 // In general, it would be preferable to implement IntoIterator for SimpleLinkedList<T>
 // instead of implementing an explicit conversion to a vector. This is because, together,
 // FromIterator and IntoIterator enable conversion between arbitrary collections.
-// Given that implementation, converting to a vector is trivial:
-//
-// let vec: Vec<_> = simple_linked_list.into_iter().collect();
 //
 // The reason this exercise's API includes an explicit conversion to Vec<T> instead
 // of IntoIterator is that implementing that interface is fairly complicated, and
 // demands more of the student than we expect at this point in the track.
+//
+// Please note that the "front" of the linked list should correspond to the "back"
+// of the vector as far as the tests are concerned.
 
 impl<T> From<SimpleLinkedList<T>> for Vec<T> {
     fn from(mut _linked_list: SimpleLinkedList<T>) -> Vec<T> {