title: Split text node
body: <p>I have div[contenteditable=true]. Text can be bold/italic/underline. </p>
  
  <pre><code>&lt;div contenteditable=true&gt;
    &lt;b&gt;Text&lt;/b&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I need to split text node to 2 blocks:.</p>
  
  <pre><code>&lt;div contenteditable=true&gt;
    &lt;b&gt;Te&lt;/b&gt;&lt;b&gt;xt&lt;/b&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>Just for Chrome and Safari.</p>