Add a concrete example that gets the job done in the README.md

[Nidal-Bakir]

[kevmoo]

This adds a LOT to the readme. I wonder if just linking to the example Flutter widgets is better.

[Nidal-Bakir]

Believe me, every Flutter dev will thank you if you add a simple example in the README.md.

I can do a simple_example.dart file if you see it would be more appropriate.

let me know what you think, Thanks.

[kevmoo]

@Nidal-Bakir - hrm. I don't want to add the dependencies.