title: add button to page with chrome extension
body: <p>is it possible to add simple button with onclick event to a page with chrome extension?</p>
  
  <p>for instance if I am looking at </p>
  
  <blockquote>
    <p>google.com</p>
  </blockquote>
  
  <pre><code>var google = document.getElementById("main");
      var button = document.createElement("button");
      var text = document.createTextNode("test");
      button.appendChild(text);
      google.appendChild(button);
  </code></pre>
  
  <p>I see my button in it?</p>