DeepCodable: Encode and decode deeply-nested data into flat Swift objects

[samdeane]

This looks cool - thanks for building it.

I haven't thought this through (), but might it be possible to collapse groups that only exist in order to access deeper structures, without needing to interpret something as a separator, using variadic arguments?:

struct SomeObject: DeepCodable {
    static let codingTree = CodingTree {
        Key("a", "b", "c") {
            Key("d1", "e1", containing: \._e1)
            Key("d2", "e2", "f2", containing: \._f2)
        }
    }
    
    
    @Value var e1: String
    @Value var f2: String
}