Typo.

docs/templates/pages/upgrading.mustache

@@ -170,7 +170,7 @@
     <h1>{{_i}}Javascript plugins{{/i}}</h1>
   </div>
   <div class="alert alert-info">
-    <strong>{{_i}}Heads up!{{/i}}</strong> {{_i}}We're rewritten just about everything for our plugins, so head on over to <a href="./javascript.html">the Javascript page</a> to learn more.{{/i}}
+    <strong>{{_i}}Heads up!{{/i}}</strong> {{_i}}We've rewritten just about everything for our plugins, so head on over to <a href="./javascript.html">the Javascript page</a> to learn more.{{/i}}
   </div>
   <h3>{{_i}}Popovers{{/i}}</h3>
   <ul>