0.1.0 Observable State
Fix the API error "can't mutate self is immutable" for BindKeyed in S… …wiftUI view (#31) Since `KeyedValueBinding` was a variable on the wrapper and wrapper was a variable on view that is structure — semantically we were mutating self. I moved it to the wrapper itself, and projectedValue now returns the wrapper, and added a subscript that is non mutating semantically.