Setup files to make fouriever installable with pip

[vandalt]

Hi @kammerje,

I cloned fouriever for the JWST pipeline and noticed it was not installable via pip. I went ahead and created a setup file for my own use. I thought it might be useful for others so I'm opening a PR. Feel free to close it if you prefer not to have this in the repo. Otherwise, let me know if there are additional changes you would want me to include here.

A few things to note:

• .gitignore includes the general Python ignored files
• Most setup things are in setup.cfg, including requirements and vesion numbers
• pyFFTW is optional and can be installed along with other requirements with pip install ".[fft]"
• pyproject.toml and __init__.py contain boilerplate code to get the build info and the version (from setup.cfg), respectively.

Thank you!

[kammerje]

Thanks a lot Thomas, this is all very helpful! I'm going to merge this into main.