Asana tasks!

See https://app.asana.com/0/11724913287040/14477880045173

- improve README.md https://app.asana.com/0/11724913287040/14477880045175
- use `@label@` to label shortcuts, objects and other things in `graph_objs_meta.py` https://app.asana.com/0/11724913287040/14477880045183
- table of content resides `graph_objs_meta-toc.py`

- and more (see commits)
@chriddyp, just to loop you in. The nice thing about fixing this in the Python API, is that it'll get caught in the same way on the backend eventually for *all*  the APIs.