Pulling some side observations out of#130

@jennybc said:

It doesn't seem like here really advertises the criteria is uses for finding the project directory. And empirically it seems like a lot of people think that only an .Rproj file "works"... where to have a bullet list of the project root criteria used by here?

@krlmlr said:

It might be time to evaluate the use ofi_am() in the wild and adapt the documentation around the intended use cases. The current focus of the "Get Started" vignette oni_am() is confusing, perhaps this really should be another vignette, and a true "Get Started" meets users at all levels where they are.