Error handling

import {
  GradeLevelAppropriatenessEvaluator,
  ConfigurationError
} from "@learning-commons/evaluators";

try {
  const evaluator = new GradeLevelAppropriatenessEvaluator(configOptions);
  const result = await evaluator.evaluate(text);
} catch (error) {
  if (error instanceof ConfigurationError) {
    console.error("Fix config:", error.message);
  } else  { ... }
}