message: Add fallback tutorial for challenges w/o one and invalid identifiers
diff: @@ -16,6 +16,7 @@ import { ForgedFeedbackInstruction } from './challenges/forgedFeedback'
  import { PasswordStrengthInstruction } from './challenges/passwordStrength'
  import { BonusPayloadInstruction } from './challenges/bonusPayload'
  import { LoginBenderInstruction } from './challenges/loginBender'
  +import { TutorialUnavailableInstruction } from './tutorialUnavailable'
  const challengeInstructions: ChallengeInstruction[] = [
  ScoreBoardInstruction,
  @@ -30,6 +31,8 @@ const challengeInstructions: ChallengeInstruction[] = [
  LoginBenderInstruction
  ]
  +const fallbackInstruction = TutorialUnavailableInstruction
  +
  export interface ChallengeInstruction {
  name: string
  hints: ChallengeHint[]
  @@ -118,7 +121,7 @@ export function hasInstructions (challengeName: String): boolean {
  }
  export async function startHackingInstructorFor (challengeName: String): Promise<void> {
  - const challengeInstruction = challengeInstructions.find(({ name }) => name === challengeName)
  + const challengeInstruction = challengeInstructions.find(({ name }) => name === challengeName) || TutorialUnavailableInstruction
  for (const hint of challengeInstruction!.hints) {
  const element = loadHint(hint)
  