Create a function that returns an array of strings sorted by length in ascending order.
sortByLength(["a", "ccc", "dddd", "bb"]) ➞ ["a", "bb", "ccc", "dddd"]
sortByLength(["apple", "pie", "shortcake"]) ➞ ["pie", "apple", "shortcake"]
sortByLength(["may", "april", "september", "august"]) ➞ ["may", "april", "august", "september"]
sortByLength([]) ➞ []