Bug - Getting started section layout is broken when navigating

[dlabaj]

Description

When navigating to about page (Getting Started --> About PatternFly) the layout breaks in several places.

• Table of Content does not expand and collapse correctly
• Content is not centered correctly
• Page horizontally expands out of the viewport
• Side nav does not auto collapse like it does in the v5 version
• Page does not adjust it's layout correctly when navigating down the page.

Screenshots

CC: @andrew-ronaldson @kmcfaul @evwilkin