Fix: 大於 -> 大於等於

參考原文：
insert will start at the beginning of the list and then keep going until it finds an element that's equal to or greater than the element that we're inserting and it will insert it just before the element.
http://learnyouahaskell.com/modules#data-list
Merge pull request #42 from guoc/patch-3

Fix: 大於 -> 大於等於