Mention inverse on demo page

demo/index.html

@@ -72,6 +72,7 @@
                 <p class="intro-text">Demos:</p>
                 <p class="intro-text">
                     <ul style="list-style: none; font-size: 22px;">
+                        <li><a href="https://inverse.chat" target="_blank" rel="noopener">As a fullscreen application</a></li>
                         <li><a href="/demo/anonymous.html">Anonymous login</a></li>
                         <li><a href="/demo/embedded.html">Single MUC chatroom embedded into the page</a></li>
                         <li><a href="/demo/without_bundled_dependencies.html">Dependencies loaded externally as &lt;script&gt; tags</a></li>