For `r-novice-inflammation`, include downloading data in setup instructions

Setup instructions in website template only explain how to install R and RStudio. Setup instructions in the lesson itself also tells learners to download [r-novice-inflammation-data.zip](https://swcarpentry.github.io/r-novice-inflammation/data/r-novice-inflammation-data.zip). It would be nice to add this instruction to the workshop websites as well so learners don't need to go into the lesson website to find it.