Added

• README file in the otfs/ directory to help direct folks to documentation for the new Duotone OTF file

Changed

• A lot of visual improvements and consistency fixes to many of the new Duotone icons
• The fa-swap-opacity class now works with parent containers where Duotone icons as children

Fixed

• Duotone SCSS files were not being correctly compiled with the Dart-Sass tool
• Font Awesome logo was not appearing in desktop application in font pickers