Index: added link to NPM

Author: staabm

pages/index.html

@@ -27,6 +27,7 @@ <h3>Installation via Package Managers</h3>
 <ul>
 <li>Bower: <code>bower install jquery-validation</code></li>
 <li><a href="https://www.nuget.org/packages/jquery.validation">NuGet</a>: <code>Install-Package jQuery.Validation</code></li>
+<li><a href="https://www.npmjs.com/package/jquery-validation">NPM</a>: <code>npm i jquery-validation</code></li>
 </ul>
 
 <h3>