Start border scale at 0

I thought putting it at the end as a disabler would be more useful but
turns out it's actually more useful for removing default borders on
elements that already have them, like `hr` for example.

By putting zero first, I can remove the default border and still apply
my own border.

src/utilities/borders.less

@@ -14,11 +14,11 @@
 
 // Base
 @border-width-scale:
+  '0' 0,
   default 1px,
   '2' 2px,
   '4' 4px,
   '8' 8px,
-  '0' 0,
 ;
 .define-border-widths(@border-width-scale; @default-border-color; @screens);