Checkpoint code from the 100 Days of SwiftUI course by Paul Hudson
- Variables - Checkpoint 1
- Arrays - Checkpoint 2
- FIZZBUZZ - Checkpoint 3
- Error Handling - Checkpoint 4
- Closures - Checkpoint 5
- Structs - Checkpoint 6
- Classes & Subclasses - Checkpoint 7
- Protocols - Checkpoint 8
- Optionals - Checkpoint 9