Sunset PyNIO

[jhamman]

PyNIO hasn't had a commit since 2019. Is it safe to assume the project is finished? Perhaps it would be worth updating the readme to articulate the status of the project.

[clyne]

Thanks for brining this to our attention @jhamman. The most up to date status with regard to the NCL suite of utilities is available here. We should indeed get this linked from the repo README.

[jhamman]

FYI, we've now marked the PyNIO backend in Xarray as deprecated (pydata/xarray#4491 (comment)).