In-Code python attribute docs

[swillisart]

From the the python docs:
If a dictionary is used to assign slots, the dictionary keys will be used as the slot names. The values of the dictionary can be used to provide per-attribute docstrings that will be recognised by inspect.getdoc() and displayed in the output of help().

Should update the base library category classes to include these instead of the comments so the UI and code can utilize them both directly as a single source.