happiness.csv vs canlang.csv in path example in reading chapter

[trevorcampbell]

We originally used happiness because it was based on our week 2 worksheet, but we should keep it consistent with the rest of the book and that chapter and use canlang

do in R version too

Edit: looking again at the figure, it seems it's based off our dsci-100-student repo structure after a few weeks of work. Should either update the fig to correspond to the current names of things or replace with a more generic figure.

I'm leaning towards just having a more generic figure to avoid having to keep it in sync

[trevorcampbell]

also specifically denote the "root" folder in the figure, since we refer to "root" in the text beforehand