We want an array, but not just any old array, an array with contents!
Write a function that produces an array with the numbers `0` to `N-1` in it.
For example, the following code will result in an array containing the numbers `0` to `4`:
```
arr(5) // => [0,1,2,3,4]
```
def arr(n=0):
    list = []
    if n == 0:
        return list
    for i in range(0, n):
        list.append(i)
    return list
def arr(n=0):
    list = []
    if n == 0:
        return list
    for i in range(0, n):
        list.append(i)
    return list