Link to GUI

docs.it4i/get-started-with-it4innovations/accessing-the-clusters/introduction.md

@@ -16,3 +16,9 @@ SSH keys
 
 Read more about [SSH keys management](shell-access-and-data-transfer/ssh-keys/).
 
+Graphical User Interface
+------------------------
+
+Read more about [X Window System](./../../accessing-the-clusters/graphical-user-interface/x-window-system/).
+
+Read more about [Virtual Network Computing (VNC)](./../../accessing-the-clusters/graphical-user-interface/vnc/).