Add Swift examples to README.md

[robbiet480]

Congrats on 0.4.0! To celebrate, I added a Swift example to the README.md. Thanks so much for Granola!

[schaefba]

Hey, thanks so much! We really appreciate this PR and think it will help people working in Swift.

We’d like to test the example code in a Swift app to put ourselves in a potential user’s shoes. It’s actually been on our agenda for a while to add an example app using Swift so we can test any issues with using Granola in a Swift environment.

We also need to add some information about the use of a bridging header in importing Granola into a Swift environment. That way we are providing the complete details necessary for someone to get Granola running in their Swift app.

We can get started on these two tasks in the next couple of weeks. If you’d like to help out with either, we'd very much appreciate it.

[robbiet480]

Hey @schaefba, great thoughts about Swift. I plan to release an app of my own in the next few weeks which uses Granola. If it would help you, i'd be more then happy to talk about my experiences building with it (haven't had a single problem other then just normal first time Swift developer issues). Since I imported with CocoaPods, I didn't even need a bridging header.

Let me know what else I can do to help.

[schaefba]

Thanks so much, that would be great!