Merge pull request #20 from nicoder/patch-1

fix typo

Author: jonrohan

README.md

@@ -1,6 +1,6 @@
 # Primer
 
-Primer is the CSS toolkit that power GitHub's front-end design. It's purposefully limited to common components to provide our developers with the most flexibility, and to keep GitHub uniquely *GitHubby*. It's built with SCSS and available via Bower, so it's easy to include all or part of it within your own project.
+Primer is the CSS toolkit that powers GitHub's front-end design. It's purposefully limited to common components to provide our developers with the most flexibility, and to keep GitHub uniquely *GitHubby*. It's built with SCSS and available via Bower, so it's easy to include all or part of it within your own project.
 
 [**Read the Primer documentation**](http://primercss.io) to learn more.