Add link to Node.js implementation in SolidificationFront2D tutorial

Author: nikoscham

tutorials/SolidificationFront2D.html

@@ -212,6 +212,11 @@ <h2 id="results"><a name="Results"></a>Results</h2>
         since the eikonal equation is solved iteratively with the Newton-Raphson method directly in your
         browser.</b
       >
+      You can find a Node.js implementation of this tutorial in the
+      <a
+        href="https://github.com/FEAScript/FEAScript-core/tree/main/examples/frontPropagationScript/SolidificationFront2D"
+        >example directory</a
+      >.
     </p>
 
     <!-- Container element where the solution plot will be rendered -->