homepage: Add FlowForge logo

Like the other companies at the list, FlowForge too uses Node-RED.
Furthermore FlowForge invests continously in the development of
Node-RED. As such I believe it could certainly be added as a new logo.

Author: ZJvandeWeg

index.html

@@ -157,6 +157,7 @@ <h3>Who's using Node-RED?</h3>
                 <li><a href="https://www.multitech.com/"><img src="users/multitech.png"/></a></li>
                 <li><a href="https://www.opto22.com/"><img src="users/opto22.png"/></a></li>
                 <li><a href="https://www.iaconnects.co.uk/"><img src="users/iaconnects.png"/></a></li>
+                <li><a href="https://www.flowforge.com/"><img src="users/flowforge.png"/></a></li>
             </ul>
             <p style="text-align:center;"><a href="/about/community/">Want to feature here? Let us know!</a></p>
             <p style="text-align:center; font-size: 0.6em; max-width: 420px; line-height: 1.2em; margin: auto; ">All logos used with permission. These links do not constitute an endorsement or approval by the Node-RED project of any of the products, services or opinions of the companies listed.</p>