<code> tags added to headings via backticks are the main culprit,
but ultimately if any elements other than text were being added to the
heading, only part of the heading would display, and any custom ID for
the heading anchor link would not be used.
* Docs/userguide switching
* Initial commit of userdocs merge
* Remove service worker, fix rendering
* Remove limited sources
* UX improvements per Paul design
* Tweak version select for FF
* Fix mobile view
* Final tweaks to UI
* Tweaks to search bar, clean up conflicts
* Fix icons
* Hide search if no API key
Steve Boyd
Guy Sartorelli
Aaron Carlino