salte-icons is a utility import that includes the definition for the iron-icon element, iron-iconset-svg element, as well as an import for the default icon set.
The salte-icons directory also includes imports for additional icon sets that can be loaded into your project.
Example loading icon set:
<link rel="import" href="../salte-icons/salte-icons.html">To use an icon from one of these sets, first prefix your iron-icon with the icon set name, followed by a colon, ":", and then the icon id.
Example using the logo icon from the salte icon set:
<iron-icon icon="salte:logo"></iron-icon>