fix: switch to small type scale - mobile

Switch to a smaller type scale for mobile devices

fix #339

sass/vars/_typography.scss

@@ -21,13 +21,15 @@ $large-font-size: 1.953rem; /* 35.16px */
 $medium-font-size: 1.563rem; /* 28.13px */
 $small-medium-font-size: 1.25rem; /* 22.50px */
 
-/* Mobile typescale based on minor third typescale with a base of 
-   100% of base font size set by the user. */
-$xxl-font-size-mobile: 2.488rem;
-$xl-font-size-mobile: 2.074rem;
-$large-font-size-mobile: 1.728rem;
-$medium-font-size-mobile: 1.44rem;
-$small-medium-font-size-mobile: 1.2rem;
+/* Mobile typescale based on a major second typescale with a base of 
+ * 100% as set by the user
+ * https://type-scale.com/?size=16&scale=1.125&text=MDN%20Web%20Docs&font=Open%20Sans&fontweight=400&bodyfont=body_font_default&bodyfontweight=400&lineheight=1.75&backgroundcolor=%23ffffff&fontcolor=%23212121&preview=true
+ */
+$xxl-font-size-mobile: 1.802rem;
+$xl-font-size-mobile: 1.602rem;
+$large-font-size-mobile: 1.424rem;
+$medium-font-size-mobile: 1.266rem;
+$small-medium-font-size-mobile: 1.125rem;
 
 $default-font-size: 1rem; /* 18px */
 $small-font-size: 0.9rem; /* 16px */