layout issues

[SerhiyAndryeyev]

Bug 1
the pages Progress and Accordion don't load:
https://widgets.dojo.io/#widget/progress/overview
https://widgets.dojo.io/#widget/accordion/overview

Expected behavior:
Pages have to be shown

Actual behavior:
Pages have not to be shown

Bug 2
when scrolling @dojo/widgets pages has not too short nav on right aside(pages Radio, Radio Group, Range Slider, etc.) it messed:
Screenshot:

Expected behavior:
The right aside nav has to be scrolling properly with the page

Actual behavior:
The right aside nav is messed up when scrolling