v0.15

Fundamental Updates

• Add type Type: BodyType in ResponseBody and, when Type is JSON, automatically impl ResponseBody<Type = JSON> for Vec<_>, [_; _], &[_], Option<_>
• Add type Error: IntoResponse in {Front, Back}Fang and updates their return type to Output = Result<(), Self::Error>

Other Changes

• Response::{json_str, set_json_str}: mark as unsafe
• Document updates