In my experience, including `"some_file.h"` is more common than `"some_file.c"`. I also like knowing at a quick glance what the entry point/main file is. That's

In my experience, including `"some_file.h"` is more common than `"some_file.c"`. I also like knowing at a quick glance what the entry point/main file is. That's less explicit when all the files have the same extension.