incorporating pivot() functions

[swmpkim]

These Tidy Data materials are awesome! I'm teaching a workshop in a few weeks and wanted to change all the gather/spread references to the updated pivot functions. I'll make some other changes for my own purposes, but thought the pptx with only those changes might be useful for others; so I made a repo, documented what I did, and put it here: https://github.com/swmpkim/tidyr_teaching_materials

If this file is helpful for y'all, I can make a pull request with it or email it to someone (or you can just grab it; I'm sure you're better at GitHub than I am). Feel free to close this issue if this is the wrong place to mention it. Thanks for all the resources!