* No need to load ggplot2, tidyverse is loaded
* Add motivation for why to pivot + minor edits
* Add an exercise on making a contingency table
* Use index.Rmd instead of rmd to make the build work
* Case study should be sentence case
* Make figure more legible and don't rely on color alone
* Streamline example + names_transform
* Potential pathway for more advanced pivot_wider
* Pivot even wider example + new unite exercise
* Update case study to use full feature pivot_wider
* Change the pregnancy exercise
* Fix chapter reference
* Remove century example since first 2 digits is not century
* Add caption to floating figure
* Align parens
* Fix referencing
* Add alt text to all chunks with plots or figures
* Remove unused figure (related to year -> century)
* Make subparts of exercises alphabetical
* Remove references to names_transform, use mutate()
* Fix code style
* Few more chp/sec reference fixes
* Put line break back
Mine Çetinkaya-Rundel
