title: Watch DOM for new elements (VanillaJS)
body: <p>I'm working on a Chrome extension, which parses the DOM and transforms some text nodes based on certain criteria. I am using pure Javascript, i.e. no jQuery or another framework, and I want to keep it that way.</p>
  
  <p>How can I watch the DOM for new dynamically inserted elements, so I can run my parser on them too?</p>
  
  <p>Again, please don't suggest any jQuery solutions, or solutions using anything but pure Javascript.</p>