Welcome to zplot.
If you just want to use zplot, a reasonably recent version is available via pip (e.g., "pip install zplot").
If you want to hack on it, you can clone it/etc. from github (e.g., "git clone https://github.com/z-plot/z-plot").
As for the files found within this repo:
The source code for zplot is stored simply here: zplot/zplot.py
The docs are found here: docs/
Most of these are auto-generated from zplot.py and the existing examples. If you wish to understand how they are generated, start with docs/Makefile and go from there. Type "make" in the docs/ directory to build the docs.
Examples are found in here: examples/
Each sub-directory contains a number of examples of different types of plots. Many of these are inspired from examples on the ploticus website (http://ploticus.sourceforge.net/doc/welcome.html)