Design onboarding / tutorial for first time users

[jorisleker]

Based on insights from user test on 25 oct that users:

• don't discover keyboard shortcuts themselves
• sometimes enter all zero's for empty fields on the paper
• sometimes don't follow the paper (i.e. correct errors before entering data)

Goal of onboarding should be:

• practice keyboard shortcuts
• instruct them fields in the application can be left blank
• instruct users how to copy the paper form.