feat(example): Add SCU pattern to FeaturePage (react-boilerplate#1178)

companion to react-boilerplate#811

the `FeaturePage` component class slipped through the cracks of react-boilerplate#811, since it used to be a functional component when it was opened... since this component is completely static, adds a `shouldComponentUpdate` that returns false and comment with explanation

app/containers/FeaturePage/index.js

@@ -14,6 +14,13 @@ import ListItem from './ListItem';
 import ListItemTitle from './ListItemTitle';
 
 export default class FeaturePage extends React.Component { // eslint-disable-line react/prefer-stateless-function
+
+  // Since state and props are static,
+  // there's no need to re-render this component
+  shouldComponentUpdate() {
+    return false;
+  }
+
   render() {
     return (
       <div>