While reviewing, I decided to draw a widget tree.  I believe it would have been easier if packs and grids were grouped.

I want to continue with 'IDLE: modernize help-about' and ditto for textview.  The help_about issue can begin with ttk conversion: change imports and remove an invalid option or two.  The textview issue can begin with the still missing docstrings.  I want to refactor both the way I discussed in the roadmap issue: make separate Toplevel and Frame subclasses.  The Toplevel subclass instance creates a Frame subclass instance which becomes an attribute of the toplevel.  Help.py already has this structure.