Load epidemics instead of installing it

Co-authored-by: Andree Valle Campos <[email protected]>

episodes/simulating-transmission.Rmd

@@ -400,13 +400,10 @@ For models that are described by ODEs, running the model actually means to solve
 In `epidemics`, the [ODE solver](https://www.boost.org/doc/libs/1_82_0/libs/numeric/odeint/doc/html/index.htm) uses the [Runge-Kutta method](https://en.wikipedia.org/wiki/Runge%E2%80%93Kutta_methods). 
 ::::::::::::::::::::::::::::::::::::::::::::::::
 
-Now we are ready to run our model. To install the `epidemics` package : 
+Now we are ready to run our model. Let's load the `epidemics` package : 
 
-```{r installation, eval = FALSE, echo = 2:3}
-# nolint start
-if (!require("pak")) install.packages("pak")
-pak::pak("epiverse-trace/epidemics")
-# nolint end
+```{r loading}
+library(epidemics)
 ```
 
 Then we specify `time_end=600` to run the model for 600 days.