title: How do I change an web.config setting using transformation syntax?
body: <p>I have a value stored in my web.config file that I would like to change when the site is published. I want to change it from TEST to LIVE.</p>
  
  <pre><code>&lt;appSettings&gt;
      &lt;add key="RequestMode" value="TEST" /&gt;
      // other keys here
  &lt;/appSettings&gt;
  </code></pre>
  
  <p>Is this possible using web.config transformation syntax? If so, how?</p>
  
  <p>Thanks.</p>