fn handle_error(&self, e: ureq::Error) -> Error {
        if e.kind() == ureq::ErrorKind::HTTP {
            Error::ProviderError(
                "Unknown topic, This topic/command might has no page in this provider yet."
                    .to_string(),
            )
        } else {
            Error::from(Box::new(e))
        }
    }
Handle the request error.
aka return a custom message if the error means that **provider** doesn't have a page for the command.
src/helper/docs/mod.rs