use shorter name for events
Add basic Doxyfile for doxygen documentation
Add primative doxygen documentation to header
major api changes

enum get a name
typedefed names end with '_t'
all api functions now can return a error code, except
spacemouse_device_list_get_next()
use pointer pointers for out arguments
in header file return types are on a separate line
make all function return negative errno on error
merge spacemouse_device_list functions into one with a update argument
use bitwise values for event types
update examples to new api
use ternary for neater error check