Register the extension with the application.

        Args:
            app (flask.Flask): The application to register with.

def init_app(self, app):
        """Register the extension with the application.

        Args:
            app (flask.Flask): The application to register with.
        """
        app.url_rule_class = partial(NavigationRule, copilot=self)
        app.context_processor(self.inject_context)