Minor updates to docfx infrastructure and improved dark mode compatibility

[banchan86]

This PR:

• Updates docfx, docfx.json and docfx-tools submodule
  • Fixes a problem with workflow padding for the example
  • Utilizes new docfx props for the Reference pages (separatepages, enum sort order)
  • Removes common logo assets now included in docfx-tools
• Converts images in article to workflow containers
  • better dark mode compatibility

At some point we will want to use the artifacts output layout and modern CI props but just thought I would issue a quick and separate update first.