future-exercises.md

1. A function cal1ed "union" that takes two arrays as arguments and returns an array of items from both arrays. For example, union([1,2,3], [4,5,6]) should return [1,2,3,4,5,6].
2. A function called "zip" that takes two arrays as arguments and returns an array of items from both arrays combined in an alternating manner. For example, zip([1,2,3], [4,5,6]) should return [1,4,2,5,3,6].
3. https://github.com/mjhea0/recursion-joy