add reference to CLI on gh-page website

index.html

@@ -60,6 +60,9 @@
                 Download your encrypted string in a HTML page with a password prompt you can upload anywhere (see <a
                     target="_blank" href="example.html">example</a>).
             </p>
+            <p>
+                The tool is also available as <a href="https://npmjs.com/package/staticrypt">a CLI on NPM</a>.
+            </p>
             <br>
 
             <h4><a class="no-style" id="toggle-concept" href="#">HOW IT WORKS ►</a></h4>