fix: update default img value; create new responsive img selector

src/utilityClasses/_displayProperties.scss

@@ -87,3 +87,13 @@ $important: null !default;
   position: absolute $important;
   width: 1px $important;
 }
+
+/// Utility class that will allow img src to fill 100% of space for responsive characteristics
+///
+/// See [variable use](http://localhost:8000/#display-utility-variable) for managing the `!important` flag.
+/// @group Display-Utility
+/// @example scss - import mixin file
+///   @import "./node_modules/@alaskaairux/orion-web-core-style-sheets/dist/utilityClasses/displayProperties";
+.util_img--responsive {
+  width: 100% $important
+}