Add middle alignment

[mabdullahsari]

Hey, thanks for your PR. 👋

Though, I'm wondering... Why would you need to be able to vertically center toast messages? It's such an odd space to utilize, especially on mobile devices. I have yet to see a toast library that does this. Could you provide a real-world example / explanation? Thanks!

[aldozumaran]

I would like to use toast as a warning message (centered), in this way it is more visible to the user (validation error, server error)

mobile example:

[mabdullahsari]

Please update the README with the new configuration when you're done.

[aldozumaran]

done! thanks

[mabdullahsari]

Please update the data provider of the ToasterHubTest to include Alignment::Middle as well.

PS: Don't miss the change requests above 😉

[aldozumaran]

done

[mabdullahsari]

done

You forgot to adjust the comment in the configuration file & README.

[aldozumaran]

sorry! updated!

[mabdullahsari]

Thanks. I'll verify if the default animation looks good with the middle alignment.

[mabdullahsari]

Thanks for your contribution. Released as 1.2.0