Add support for utoipa

[JohnScience]

I would like to use zxcvbn::feedback::Feedback as a field in an enum error type that is converted to JSON and returned in this form from an endpoint.

To generate Swagger documentation, I use utoipa.

To display the return type in Swagger documentation, I need to have the implementation of utoipa::ToSchema trait for zxcvbn::feedback::Feedback. Such implementation can be easily provided for a locally-defined item (e.g. a struct or an enum) via utoipa::ToSchema derive macro:

For example,

#[derive(ToSchema)]
struct Pet {
    #[schema(example = 1, default = 0)]
    id: u64,
    name: String,
    age: Option<i32>,
}

As a downstream user of both utoipa and zxcvbn, the easiest and the most logical option for me right now is to fork zxcvbn and use the patched fork instead of the original zxcvbn.

However, I'd love to see a utoipa feature in zxcvbn that would enable utoipa::ToSchema derive macro calls.

Thank you in advance!