Update extend section

index.html

@@ -100,13 +100,11 @@
       <li><code>site disable</code>: stop the server and remove it from startup items.</li>
       </ul>
 
-      <h2 id="extend">Extend</h2>
-
-      <p>You can extend Site.js and create your own dynamic servers using Node.js:</p>
+      <h2 id="extend">Use as a module</h2>
 
       <pre><code>npm i @ind.ie/site.js</code></pre>
 
-      <p>Create your own dynamic web apps in Node.js using the <a href="https://source.ind.ie/site.js/app#api">API</a>.</p>
+      <p>You can use Site.js as a module in your Node.js projects. See the <a href="https://source.ind.ie/site.js/app#api">API documentation</a> for details.</p>
 
       <h2 id="learn-more">Learn more</h2>