update so that VPN and DoX links now points to SEGI english description + remove images associated to old explanations

_sidebar.md

@@ -23,21 +23,16 @@
 <summary>[Quick Start](mass-storage/quickstart-mass-storage)</summary>
 
    - [Rules to follow](mass-storage/quickstart-mass-storage#important-rules-to-follow-on-the-mass-storage)
-   - [VPN connection](vpn-connection)
    - [Mass storage connection](mass-storage/mass-storage-connection)
    - [Billing system](mass-storage/mass-storage-billing)
 </details>
 <br>
 </details>
 
-<details>
-<summary>[Dox](dox/dox_home)</summary> 
+[Dox](https://my.segi.uliege.be/cms/c_11346464/en/mysegi-presentation)
 
-   - [Installation](dox/dox-installation)
-   - [Setup](dox/dox-setup)
-   - [Possibilities](dox/dox_home#possibilities)
-   - [Recommendations](dox/dox_home#recommendations)
 </details>
+
 <br>
 
 [**Cluster**](cluster/cluster-home)
@@ -47,5 +42,3 @@
 [**FAQ**](faq/FAQ)
 
 [**Contacts**](contacts)
-
-