Automate updating the dotscience-python reference section on dotsciecnce docs when the README.md is changed.

It's a manual process to copy the latest dotscience-python readme.md into https://github.com/dotmesh-io/dotscience-docs/blob/master/hugo/content/references/dotscience-python-library.md and it's often forgotten. 

Automating this on CI integration would be nice to have.