Headings are not hierarchical

Suggestions for fixes as part of the WCAG 2.0 accessibility audit of the UI options tools 

A heading that introduces the component would be beneficial to users for the added context and organization. Ex. <h2>Preferences Editor</h2>, with the sub-headings then changed to <h3>s.

Table of Contents should be a H2 as H1 are generally reserved for site title or main titles.