add map function for grays

scss/_functions.scss

@@ -72,6 +72,10 @@
   @return map-get($theme-colors, $key);
 }
 
+@function grayscale($key: "100") {
+  @return map-get($grays, $key);
+}
+
 // Request a theme color level
 @function theme-color-level($color-name: "primary", $level: 0) {
   $color: theme-color($color-name);