Add PyPi package

[nateraw]

Love this work! However, as I've been toying around with pixray the last day or so, and have had quite a hard time installing everything from scratch... all the git submodule business + local setup.py installs + (😱 gasp) appending to sys path to make things work feels really sketchy!

Is a PyPi package on your roadmap? Something where I could go pip install pixray (or pip install pixray[<some-extra>] if you wanted to separate out the extra demo dependencies) would be super nice and would make this work a lot more accessible to folks!

[dribnet]

Good request - though note there are no submodules in this repo - just an upstream dependency on diffvg - so really we need a setup.py there I think.

I believe the main pain point will be putting all the code into a subdirectory that would then be the library. But a lot of the hard work (like requirements.txt) has already been done, etc.