Typo fix (#915)

docs/_docs/15-utility-classes.md

@@ -9,7 +9,7 @@ modified: 2016-11-03T11:32:25-04:00
 
 Using the Kramdown Markdown renderer with Jekyll allows you to add [block](http://kramdown.gettalong.org/quickref.html#block-attributes) and [inline attributes](http://kramdown.gettalong.org/quickref.html#inline-attributes). This is nice if you want to add custom styling to text and image, and still write in Markdown.
 
-**Jekyll 3:** Kramdown is the default for `jekyll new` sites and those hosted on GitHub Pages. Not using Kramdonw? That's OK. The following classes are still available when used with standard HTML.
+**Jekyll 3:** Kramdown is the default for `jekyll new` sites and those hosted on GitHub Pages. Not using Kramdown? That's OK. The following classes are still available when used with standard HTML.
 {: .notice--warning}
 
 ## Text Alignment
@@ -172,4 +172,4 @@ You can also add the `.notice` class to a `<div>` element.
 <div class="notice--info">
   <h4>Notice Headline:</h4>
   {{ notice-text | markdownify }}
-</div>
+</div>