Make the notebook table stacked since we don't have Julia

All I have don't here @mmcky is add a HTML table row between the first and second cell.
<tr><td>content cell 1</td><.tr>
<tr><td>content cell 2</td></tr>

I hope this is what you were after.

website/notebooks.html

@@ -33,6 +33,8 @@ <h2>Notebooks</h2>
                         <tbody>
                             <tr>
                                 <td>Python</td>
+			    </tr>
+			    <tr>
                                 <td><a href="https://github.com/QuantEcon/book-networks-public/tree/main/notebooks">Files on GitHub</a></td>
                             </tr>
                         </tbody>
@@ -82,4 +84,4 @@ <h2>Links</h2>
 
 </body>
 
-</html>
+</html>