Currently, time makes use of a custom erfa_time.pyx file, which vectorizes the erfa functions, with documentation cut&paste'd from the erfa.c file.

Following a comment by @eteq in #1418, this issue is to remind us/suggest it would be best to standardize the interface, ensuring, e.g., that the call sequences have the same name, and that the documentation is automatically copied. Likely, the result should be in utils, since presumably other packages will need sofa functionality.

(It may be useful to check if other packages, such as pysofa, have already automated this)

EDIT: given bugs like #1929, which resulted from one erfa routine giving results in 'm' and another expecting input in 'km', it may be worth considering whether we should use quantities throughout the python interface to erfa. Of course, that implies the interface lives in astropy rather than in erfa itself.