Correct statement re: cause of unordered iteration
Correct statement re: cause of unordered iteration

My previous commit stated that `enum`s provide unordered iteration because they 
_are_ `Map`s.  That is incorrect.  `enum`s provide unordered iteration because the
relevant iteration methods _create_ a corresponding `Map` to iterate over.

This commit corrects that misstatement.
MasterDuke17/doc,MasterDuke17/doc,tbrowder/doc,MasterDuke17/doc,tbrowder/doc,MasterDuke17/doc,tbrowder/doc,tbrowder/doc