fix code annotation (Fix #48)

Author: avallecam

episodes/simulating-transmission.Rmd

@@ -489,7 +489,7 @@ We ran our model with $R_0= 1.5$. However, we believe that $R_0$ follows a norma
 1. Obtain 100 samples from the from a normal distribution
 
 ```{r normal, echo = TRUE}
-# get mean mean and sd over time
+# specify the mean and standard deviation of R0
 r_estimate_mean <- 1.5
 r_estimate_sd <- 0.05