[ ] header- list and link datasets depress, Addhealth, Lung function
[ ] 1.2 add explanation about using here::here to import data
[ ] 1.3.4 comment on par(mfrow=c(1,2)) to explain this is only setting up the plot environment for 2 visualizations? could pull from 1.6.3
[ ] 1.3.4 hidden change of age=41 values to 9 could be confusing if a student visualizes/summarizes their own data and sees different results before reading 1.3.5
[ ] 1.3.6. blank section - add text and demo
[ ] 1.3.7. Addhealth dataset needs introduction here or just at header
[ ] 1.4.3 all 2/1 binary variables are no=2 so replacing binary gender variable example with one of them won't work.. could just resolve the issue marker and leave note about data being collected in the 70s or could pull in Addhealth dataset like in 1.3.7