Replace car data vignette with relevant example

[eribul]

• [x] I would have preferred that the trivial example from the vignette coder actually be a simple example of classifying patients into groups based on ICD codes, rather than an unrelated example based on car makes and models. You could also show in this vignette how the ex_carbrands classcodes object was created. I found myself wondering that as I read the vignette.
• [x] Under the "Interpretation" section, the listed names are mostly not in line with the actual output printed above. I assume you changed the contents of the example datasets and did not change the corresponding vignette text so this should be updated.
• [x] In fact, the example on the README page is much more relevant and could easily be expanded to demonstrate the functionality in place of the car brand example. Maybe both are not needed.

[eribul]

drgtwo:

One thing that's missing from the documentation (for functions, the README, and the vignettes) is an example of what someone would do with the output of the package. The example in the "coder" vignette isn't healthcare-related, instead focused on a toy example involving patient cars. Perhaps replace it with a vignette that works through a "real" example, and shows at least one result from it that would be similar to what your next typical step would be. Besides being more interesting, it serves as documentation for the output: if you created a histogram of Charlson indices, it brings the user's attention to the importance of that column. You could add something from the result of your ex_people and ex_icd10, but that join has only a single positive result (one patient with peripheral vascular disease). Of course real healthcare data is necessarily private, but you could instead consider taking a small sample of rows and columns from the SynPUF data, which is synthetic emergency room data including admissions and diagnoses. After using coder to determine what diagnoses occurred after an emergency room visit, the vignette could get one or two results from the data (e.g. showing the average Charlson comorbidity index of emergency room admissions over time, creating a histogram of them, or showing the most common diagnoses within the window). This would help communicate why it's helpful to annotate a dataset in this way. (You don't need to use a sample from SynPUF if you don't want to; you could also just construct the simulated data to have more joined diagnoses).

[eribul]

Review: I agree that the toy exampl ewith car data, as presented in the coder vignette seems redundant to the README and to the comorbidity vignette. I have therefore deletaed this vignette!