Organize functions into fewer files

[howardbaik]

Currently, this package's R/ directory contains one file for each function. So, the file demo-crowding.R contains demo_crowding(), the file demo-education.R contains demo_education(), and so on.

According to the "R code" chapter in R Packages, this extreme is bad. I suggest we have a single .R file contain a family of related functions. For ex, demo.R would contain all the demo_*() functions, handle.R would contain all the handle_*() functions, and so on.

[realbp]

Would love to talk more about this because I am all for organization! But for now, Sean has told me to keep the r files linear

[howardbaik]

Sure, I'll talk to Sean tomorrow about this. Would love to learn about his reasoning.