Outputs the specified Font Awesome icon. Attributes include:
- icon: The name of the icon; accepts any name below (or browse at http://fontawesome.io/.
- color: The icon color; accepts “primary”, “secondary”, “action”. (optional; inherits default from element).
- size: The icon size; accepts “lg”, “2x”, “3x”, “4x”, “5x”. (optional; inherits font size from element).