Add detailed license information in setup.cfg

[MattTheCuber]

No description provided.

[william-silversmith]

Hi Matt!

Thanks so much for the PR, it shows a level of caring about this project that I really appreciate. However, unfortunately putting License TROVE classifiers in the metadata is deprecated in this year's python ecosystem (I forget if it's pip, twine, or setuptools that is the issue...) and breaks the build. The new standard is to put an SPDX identifier in the license field, which is something I've been migrating all my projects to.

https://discuss.python.org/t/pep-639-round-3-improving-license-clarity-with-better-package-metadata/53020

[MattTheCuber]

Oh, interesting. Licensecheck fails to read the license from this library, so I thought that adding this would fix it. Do you have any other ideas to resolve this problem? Maybe it is a problem with licensecheck? None of the other libraries we used from seung-lab fail (cc3d, edt, etc.)...