[Example] Flutter - Adding an image as an overlay

[aashish-g03]

Hi @colbyfayock ,

I noticed there's no transformation example for Flutter. I'd like to contribute by adding an example for the Flutter SDK. The example will involve adding an image overlay to an existing image, similar to the Dart example provided here:

Cloudinary Dart Example

I plan to implement this in Flutter. Could you please assign the issue to me? Let me know your thoughts!

[colbyfayock]

go for it! we can do one at a time, you can start with this one!

[aashish-g03]

@colbyfayock I've created the PR.
Thanks for the opportunity to contribute to the Cloudinary repository. Could you please review my PR?