pub fn add_link(
        &mut self,
        description: impl Into<String>,
        url: impl Into<String>,
    ) -> &mut Self {
        self.links.append(&mut vec![HelpLink {
            description: description.into(),
            url: url.into(),
        }]);
        self
    }
Adds a [`HelpLink`] to [`Help`]'s `links` vector.
tonic-types/src/richer_error/std_messages/help.rs