use correct+newer name for retina mixin in docs; fixes #12450

diff --git a/css.html b/css.html
index 74f46cac0c01c9a24bcc8165a6f100d9ce9553d2..0f2d79c27dd14a8c2f1b2ed0d35f87495b6216db 100644 (file)
--- a/css.html
+++ b/css.html
@@ -3283,7 +3283,7 @@ a {
 
 // Usage
 .jumbotron {
-  .retina-image("/img/bg-1x.png", "/img/bg-2x.png", 100px, 100px);
+  .img-retina("/img/bg-1x.png", "/img/bg-2x.png", 100px, 100px);
 }
 {% endhighlight %}
 </div>