Correct presented class for outline buttons

docs/components/buttons.md

@@ -57,7 +57,7 @@ When using button classes on `<a>` elements that are used to trigger in-page fun
 
 ## Outline buttons
 
-In need of a button, but not the hefty background colors they bring? Replace the default modifier classes with the `.btn-outline-*` ones to remove all background images and colors on any button.
+In need of a button, but not the hefty background colors they bring? Replace the default modifier classes with the `.btn-*-outline` ones to remove all background images and colors on any button.
 
 {% example html %}
 <button type="button" class="btn btn-primary-outline">Primary</button>