Backport #34937

Update a URL mentioning dead name

Author: XhmikosR

scss/mixins/_screen-reader.scss

@@ -1,7 +1,7 @@
 // Only display content to screen readers
 //
 // See: https://www.a11yproject.com/posts/2013-01-11-how-to-hide-content/
-// See: https://hugogiraudel.com/2016/10/13/css-hide-and-seek/
+// See: https://kittygiraudel.com/2016/10/13/css-hide-and-seek/
 
 @mixin sr-only() {
   position: absolute;