Questionnaire RST code validation for detecting the teacher's mistakes

[atilante]

This is a little idea for usability improvement. The Questionnaire directive could validate its input and prevent the human error below. Both the "Yes" and "No" options have identifier a.

  .. pick-one:: 1

    **Question 13.** If you answered **Yes** to Question 12, can you apply any
    such algorithm in practise (not necessarily in code)?

    *a. Yes
    *a. No

That is, the questionnaire directive could validate that:

• All the identifying letters in the options of a pick-one or pick-any question are unique (otherwise compile error)
• There is at least one correct answer (otherwise compile warning)

[markkuriekkinen]

Thanks, these are very good ideas!