Add more information to the interaction guidelines / make them customizable

[thoughtsky]

As a volunteer, I want to receive precise information on the safety measures and precautions I have to take while delivering a box, so that I do not endanger anyone else or myself.

As an organizer, I want to be able to give volunteers precise information on the safety measures and interaction guidelines, so that we can follow the most recent local / national guidelines for a safe interaction.

This epic spans two flows right now - they might need to be divided into two epics later on.