How to: Create URL
This API should create a new short URL in our system given an original URL.

```tsx
createURL(apiKey: string, originalURL: string, expiration?: Date): string
```

**Parameters**

API Key (`string`): API key provided by the user.

Original URL (`string`): Original URL to be shortened.

Expiration (`Date`): Expiration date of the new URL _(optional)_.

**Returns**

Short URL (`string`): New shortened URL.