Add command-line interface

[ofgulban]

Hi Michael,

I was planning to use your nice package but wanted to a command line interface. While adding the interface, I took some liberties to improve upon your work. Changes are mainly:

• Optimized example gifs (readme was loading too slow on mobile)
• Reorganized the structure for better packaging
• Added docstrings to functions following PEP257 and scipy-numpy style.
• Added setup
• Added command-line interface
• Revamped readme
• Reworked the old-style examples and moved them to their own folder.
• Tested to confirm all the commands in readme and scripts in examples are working in a fresh python environment.

I suggest changing the name of the repo from gif_your_brain to gif_your_nifti. As you say in readme, it works for any 3D nifti anyway.

I recommend you create a release of the old version and if you accept these changes you can create a new release. If you think these changes are too extensive, feel free to reject the PR. I am cool with maintaining this version from my fork and create new releases there :)

Cheers

[miykael]

This is all perfect! Thank you very much for cleaning this and making a cli out of it. Will merge.

[ofgulban]

Thanks, enjoy :)