add introduction episode for the Late Task

> > 4. • "In this tutorial, we will learn how to choose an existing model to generate predictions for a given scenario." I think it'd be very important to clarify the types of modelling according to the purpose of the analysis in epi/outbreak analysis, e.g., the difference between forecasts/scenario modelling/retrospective analysis, either as part of the tutorial or as pre-requisite and clarify which one is intended in this episode. The episode goes into detail about stochastic vs deterministic, but doesn't mention this consideration, which I believe would be very significant for learners, especially for epidemiologists or clinicians new to modelling. Since the episode is quite short, and the purpose is to guide readers on choosing a modelling approach, I think a section about model purposes/applications would be a valuable addition.
>
> I think this could be added to the introduction episode epiverse-trace/tutorials#67

_Originally posted by @amanda-minter in https://github.com/epiverse-trace/tutorials/issues/63#issuecomment-1824233014_