Split the repo into i3-py and i3-py-examples

[janoliver]

Hi, I suggest splitting the repo into two, i3-py, which has the library code in it, and i3-py-examples for the examples. Pip only installes the library, which is fine. Most people will want their custom scripts using it in something like ~/.config/i3/contrib or so, so it would be great if they could just clone the example repo into that folder.