docs(examples): Added missing word in paper.html

Closes #1314

Author: michaelkrog

example/web/paper.html

@@ -47,7 +47,7 @@ <h2>Events: paper-checkbox</h2>
     <div>
         <paper-checkbox on-change="curValue = curValue == 5 ? 2 : curValue == 2 ? 10 : 5"></paper-checkbox>
     </div>
-    <p>Every the value changes, the curValue ({{curValue}}) scope variable will update</p>
+    <p>Every time the value changes, the curValue ({{curValue}}) scope variable will update</p>
 
     <h2>Two-way binding: paper-slider</h2>
     <p>The slide is bound to the curValue scope variable ({{curValue}})</p>