Fixup low-level documentation
Fixup low-level documentation

jupyter-widgets/ipywidgets,jupyter-widgets/ipywidgets,SylvainCorlay/ipywidgets,cornhundred/ipywidgets,cornhundred/ipywidgets,ipython/ipywidgets,cornhundred/ipywidgets,SylvainCorlay/ipywidgets,SylvainCorlay/ipywidgets,SylvainCorlay/ipywidgets,ipython/ipywidgets,ipython/ipywidgets,ipython/ipywidgets,ipython/ipywidgets,cornhundred/ipywidgets,cornhundred/ipywidgets,jupyter-widgets/ipywidgets,jupyter-widgets/ipywidgets