Doc needs refresh

[gwenblum]

This is the published doc: https://steelscript.readthedocs.io/en/latest/
See the source in the docs folder in the main repo for steelscript (https://github.com/riverbed/steelscript/tree/master/docs) and in the repo of each module (e.g. https://github.com/riverbed/steelscript-netim/tree/master/docs )

• Quick start should be docker first or pip from github first (ref quickstart of the README.md)
• Some modules are missing
• Readthedocs build fails
• Sphinx extension "cython_highlighting" fails