Quiz Lint: Check for intro slides. (2)

In almost all quizzes, it makes no sense to directly start with a question, as that would mean that the presenter has no time to show the slides or go full screen. The quiz linter could remind an organizer to have introduction slides, such that the quiz does not start with a question.

• Make a check for an introduction slide in the Quiz Linter front-end class and check if the necessary information is available (1).
• Generate a front-end warning in the Quiz Linter (1).