title: Webpage preview npmjs using Angular
body: <p>I'm trying to implement this package in my project <code>npm install webpage-preview</code>, but I don't know where can I put this code, the <code>webpagePreview</code> is <code>undefined</code>. Is this just for angularjs or I missed something?</p>
  
  <pre><code>webpagePreview.generatePreview('http://www.google.com/', 'google',
      APP_ROOT + '/public/previews', null, null, function(error, sizePaths) {
      if (error) {
          console.log(error);
      }
      else {
          console.log(sizePaths);
      }
  });
  </code></pre>