add group challenges per set of episodes

Following the social-constructivism learning theory ([Kay et al., 2016](https://journals.physiology.org/doi/full/10.1152/advan.00132.2015)), adapt summative assessments as task-oriented challenges with a relevant or related public health question. We can work to adapt them to the local context of the learners. From simulated data or historically-registered local outbreaks. These aim to complement the individual tutorial activity with a challenge to resolve in groups and present to decision-makers.

This will assess abilities to:
- translate estimates to immediate practice.
- distribute individual abilities in favour of a group response.
- communication abilities in software and speaking.
- focusing on a specific story, the diagnosis of the problem, to facilitate the response and reaction of decision-makers.