implementation package?

[kelle]

I suspect all of us are writing implementations of this DM - adding and checking the keywords. (Here is the current state of my scripts for implementing in FITS: https://github.com/astrodbtoolkit/astrodb_utils/blob/main/astrodb_utils/fits.py)

I'm curious if we should work collaboratively on a dedicated package to do this. or should these writers and validators be in specutils? or in pyvo? or is this wheel small enough we should just all re-invent it?