Moved Advanced Cart to apps

Author: obuisard

…nd-extensions/j2commerce_advancedcart.md …tensions/apps/j2commerce_advancedcart.mdwebsite/docs-v6/apps-and-extensions/j2commerce_advancedcart.md renamed to website/docs-v6/apps-and-extensions/apps/j2commerce_advancedcart.md website/docs-v6/apps-and-extensions/j2commerce_advancedcart.md renamed to website/docs-v6/apps-and-extensions/apps/j2commerce_advancedcart.md

@@ -139,7 +139,6 @@ const sidebars = {
                         },
                     ],
                 },
-                'apps-and-extensions/advanced_cart',
             ],
         },
         {