title: How to create and use XML namespace?
body: <p>I want a page like this:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;html xmlns="http://www.w3.org/1999/xhtml"
        xmlns:m="mine.xsd"&gt;
      &lt;m:dialog m:title="Hello"&gt;Hi there!&lt;/m:dialog&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>How can I write "mine.xsd"?</p>