Make graph_objs.py compatible with new graph reference!

- created from @theengineear 's factories branch
- adapt graph reference INFO to new graph reference structure
- add doc content (e.g. links to plot.ly examples and parent keys for a given obj)

not now, but eventually we'll want graph reference to deliver both 'all categories' and 'style categories'  (perhaps data categories?) for this purpose. If we were to create a new category in grpah_reference, we'd have to make a hard-coded change in this file. food for thought.