add VS Code Tunnel recommendations

config/templates/hpc.template

@@ -59,6 +59,7 @@ nav:
       - OpenFOAM: openFOAM.md
       - Python: python.md
       - Python virtual environments: setting_up_python_virtual_environments.md
+      - VS Code Tunnel: vscodetunnel.md
   - FAQ:
       - Frequently Asked Questions: FAQ.md
   - Appendices:

mkdocs/docs/HPC/vscodetunnel.md

@@ -0,0 +1,57 @@
+# VS Code Tunnel
+
+Please keep in mind, that this is not a `VS Code` manual,
+it is only our recommendation how to connect to the {{ hpcinfra }} using the `VS Code` tunnel. 
+
+For `VS Code` documentation, see <https://code.visualstudio.com/docs>
+
+We only support `VS Code` tunnel access via the `VS Code` application (installed locally).
+To connect to the `VS Code` tunnel using the URL via a web browser is not supported,
+since web access might not work from all browser or operational system.
+The only confirmed way to connect via a browser is using Windows 11 and Edge. 
+
+## Prerequisites
+
+We do recommend to install the [remote development](https://code.visualstudio.com/docs/remote/remote-overview)
+extension pack for the `VS Code` App.
+
+
+## Connection
+
+In the [web portal](./web_portal.md), under the "Interactive Apps" choose `VS Code` Tunnel,
+select the parameters and launch your job by clicking ++"Launch"++
+When your job has started, connect by clicking ++"Connect"++
+
+In the new browser tab or window, for the question
+`How would you like to log in to Visual Studio Code?` choose `Microsoft Account` 
+(using the arrow keys on your keyboard, then hit ++"Enter"++).
+Then follow the instruction to authenticate yourself.
+
+!!! Warning
+
+    If you are an UGent user, and you get an error message something like "You do not have access to this"
+    during the Microsoft Authentication, then you might have to
+    [whitelist yourself](https://dictselfservice.ugent.be/index.php?page=requestform&form=deviceCodeAuth)
+    You can use as motivation "Needed for `VS Code` tunnel for HPC" (You have to do it only once.)
+
+    Please be aware, that it might take up to half an hour until the whitelisting become effective.
+
+
+If you are not connected automatically to the tunnel, please select "connect to..." and then
+"Connect to Tunnel" using Microsoft Account and select the tunnel named `vsc-<your vsc account>-<cluster>`.
+Please note that right now you can only have one tunnel per cluster.
+
+If you are asked to update `VS Code` CLI on your remote server, choose ++"Not Now"++.
+You do not have permission to update the CLI, as it is centrally installed.
+This means that your `VS Code` App is newer than the CLI on our systems.
+We update the centrally installed CLI time to time,
+but the upgrade rate of the App/CLI is very high,
+so it is hard for us to follow it tightly.
+If you suspect that the too old version of CLI might cause problem, please send us a
+[software installation request](https://www.ugent.be/hpc/en/support/software-installation-request)
+for `code-cli`. 
+
+Please do not use `VS Code` to ssh to the login nodes,
+but always use a `VS Code` Tunnel connection,
+preferably using the [interactive and debug cluster](./interactive_debug.md) 
+