define-runtime-path with directories

[LiberalArtist]

On Slack, @greghendershott suggested to someone that, if you need to use define-runtime-path with several files in the same directory, you might do something like:

(define-runtime-path here ".")
(define a (build-path here "a"))
(define b (build-path here "b"))

I have done this often, but I was never clear on how this pattern interacts with define-runtime-path's function of telling the executable creator which files to include in a distribution. (I've never actually used the executable creator in practice.)

I decided to try an experiment (https://github.com/LiberalArtist/runtime-path-example), and, while the executable creator did package everything needed, I'm not sure its behavior is really desirable: it included everything in the here directory and its recursive sub-directories, including editor backups and the complete contents of the ".git" directory.

Assuming this is the intended behavior, I think it should be mentioned in the documentation. Documenting "The Right Thing" to do for multiple files in the same directory would probably also be good: as I said, I've used the approach @greghendershott suggested a number of times.