FLUID-4323: Add the Self-voicing panel to the fat panel
Merge remote-tracking branch 'acheetham/FLUID-4323-demo' into demo

* acheetham/FLUID-4323-demo:
  FLUID-4323: Add the Self-voicing panel to the fat panel
FLUID-4323: Add simplified content as independent panel; convert TOC back to TOC-only
Merge remote-tracking branch 'upstream/demo' into FLUID-4323-demo
FLUID-4323: Adjust size of fat panel to remove scrolling inside the fat panel
Merge remote-tracking branch 'acheetham/FLUID-4323-demo' into demo

* acheetham/FLUID-4323-demo:
  FLUID-4323: Adjust size of fat panel to remove scrolling inside the fat panel
  FLUID-4323: Add simplified content as independent panel; convert TOC back to TOC-only