refactor: cleanup sidebar

_sidebar.md

@@ -3,25 +3,11 @@
     * Getting started
         * [Quick start](en-en/QUIQQER/quickstart.md)
         * [Installation](en-en/QUIQQER/installation.md)
-        * [Configuration](en-en/QUIQQER/configuration.md)
     
-    + Modules
-        * [ERP](en-en/modules/ERP/README.md)
-            * [Invoice](en-en/modules/ERP/Invoice)
-            * [Order](en-en/modules/ERP/Order)
-            * [Products](en-en/modules/ERP/Products)
-
 * Deutsch
 
     * Los geht's
     
       * [Quick start](de-de/QUIQQER/quickstart.md)
       * [Installation](de-de/QUIQQER/installation.md)
-      * [Konfiguration](de-de/QUIQQER/configuration.md)
-      
-    + Modules
-        * [ERP](de-de/modules/ERP/README.md)
-            * [Invoice](de-de/modules/ERP/Invoice/README.md)
-            * [Order](de-de/modules/ERP/Order/README.md)
-            * [Products](de-de/modules/ERP/Products/README.md)
-      
+