Create examples folder within docs with python scripts from docs

[Dr. Andrew Annex]

A great GSoC contribution would be to make a new folder in the docs folder that can contain a collection of example spice python scripts, ideally the ones already within the doc rst files could be used to start. I wonder if sphinx could render those files out within the read the docs build to avoid duplicate codes. The RST docs should include links to these files at the header of the corresponding code blocks so that users can just download the code directly.