add talwindcss support 

add support with talwindcss in the className configuration option 

Example:
```js
import Toastify from 'toastify-js'

Toastify({
  className: "flex items-center justify-center text-xl md:text-3xl flex-wrap bg-gradient-to-b from-red-500 to-red-800 text-white dark:bg-[#111] dark:text-[#ccc] ..."
  // others options toast
})
```