update template

Author: luajalla

docs/tools/templates/template.cshtml

@@ -49,7 +49,7 @@
             <li class="nav-header">Documentation</li>
             <li><a href="@Root/reference/index.html">API Reference</a></li>
             <li><a href="@Root/compatibility.html">Excel Compatibility</a></li>
-            <li><a href="@Root/openofficediff.html">OpenOffice Differeces</a></li>
+            <li><a href="@Root/openofficediff.html">OpenOffice Differences</a></li>
           </ul>
         </div>
       </div>