Updated the normalise css.

sass/init/visually-hidden/_visually-hidden.scss

@@ -4,8 +4,6 @@
 //
 // Make an element visually hidden, but accessible to screen readers, etc.
 // @see http://snook.ca/archives/html_and_css/hiding-content-for-accessibility
-//
-// Style guide: sass.mixins.visually-hidden
 @mixin visually-hidden {
   position: absolute !important;
   height: 1px;
@@ -18,8 +16,6 @@
 // visually-hidden--off()
 //
 // Turns off the visually-hidden effect.
-//
-// Style guide: sass.mixins.visually-hidden--off
 @mixin visually-hidden--off {
   position: static !important;
   clip: auto;
@@ -32,8 +28,6 @@
 //
 // Makes an element visually hidden by default, but visible when receiving
 // focus.
-//
-// Style guide: sass.mixins.visually-hidden--focusable
 @mixin visually-hidden--focusable {
   @include visually-hidden;