Add asdf-astropy as a coordinated package - #490

Tagging @nden and @perrygreenfield to confirm they will be maintainers.

I am OK with being a maintainer

I suggest to add a CITATION file to the repo as well.

Thank you for proposing this package as an affiliated a coordinated package! I'm happy to confirm that your package is now under review and we'll post the results of the review here and on the mailing list.

I confirm that I will be a maintainer.

This package has been reviewed for inclusion in the Astropy affiliated coordinated package ecosystem by yours truly, and I have synthesized the results of the review here.

You can find out more about our review criteria in Reviewing affiliated packages. For each of the review categories below we have listed the score and have included some comments when the score is not green.

Functionality/Scope
No further comments
Integration with Astropy ecosystem
This was astropy.io.misc.asdf, so naturally it is already very well-integrated.
Documentation
Documentation is there but now that this is its own package, it could be expanded but nothing fundamental is "missing," so I gave it a green instead of orange. I opened follow up issues at asdf-astropy#72, asdf-astropy#73, and asdf-astropy#74 but none of them are blockers.
Testing
Uses GitHub Actions and tox, with extensive workflows and test matrix set up. Coverage is at 93%. The test suite appears to be in very good shape!
Development status
Last release was as recent as last month. I see a healthy amount of commit activities. The issues I opened seem to have short response time. Given that DKIST, JWST, and possibly Roman are investing heavily into ASDF support, I am not worried about this package getting unmaintained in the near future.
Python 3 compatibility
Test suite covers Python 3.8-3.10. I have inquired about Python 3.6 and 3.7 support at asdf-astropy#75 and asdf-astropy#76, but they are not blockers.

Summary/Decision: Everything looks great, and we're happy to confirm that this package will be accepted as an affiliated a coordinated package after a 2-week comment period (ends on 2022-06-02) for a chance for the Astropy community to speak up! 🏆

If you have any follow-up questions or disagree with any of the comments above, leave a comment and we can discuss it here. At any point in future you can request a re-review of the package if you believe any of the scores should be updated - contact the affiliated package editors listed on the Astropy team page, and we will do a new review.