The well known `split()` method splits a string into an array of substrings by looking for a separator, and returns the new array. The goal of this challenge is to split a string, by using a separator, but in the type system!
For example:
```ts
type result = Split<'Hi! How are you?', ' '> // should be ['Hi!', 'How', 'are', 'you?']
```
