Adding infectiousness according to time (not for V1, probably for V2)

[DAM-Philippon]

It would be nice to add time-dependent infectiousness to the Individual agents or Biological entities.

A possible workaround would be to use the serial interval distribution as the infectiousness of an Individual at time t, after exposure.

One difficult part would be to consider the different infectious periods represented: should we truncate the serial interval distribution, or should we simply use it and try to find the parameters of the infectiousness through time according to the infectious period limits.