fix links to gitlab help pages

fix links, triggered by these errors:

https://gitlab.hzdr.de/hifis/overall/hifis-technical-documentation/-/jobs/665266#L556

docs/software/gitlab/getting-started.md

@@ -101,11 +101,11 @@ The process looks like this:
 4. [Verify that you can connect. :fontawesome-solid-up-right-from-square:][verify-ssh]
 
 !!! info
-    * Setup Git and SSH: <https://gitlab.hzdr.de/help/ssh/index.md>
+    * Setup Git and SSH: <https://gitlab.hzdr.de/help/user/ssh.md>
     * On Windows: Please additionally refer to
-      <https://gitlab.hzdr.de/help/ssh/index.md#use-ssh-on-microsoft-windows>
+      <https://gitlab.hzdr.de/help/user/ssh.md#use-ssh-on-microsoft-windows>
 
-[existing-ssh]: https://gitlab.hzdr.de/help/ssh/index.md#see-if-you-have-an-existing-ssh-key-pair
-[create-ssh]: https://gitlab.hzdr.de/help/ssh/index.md#generate-an-ssh-key-pair
-[add-ssh]: https://gitlab.hzdr.de/help/ssh/index.md#add-an-ssh-key-to-your-gitlab-account
-[verify-ssh]: https://gitlab.hzdr.de/help/ssh/index.md#verify-that-you-can-connect
+[existing-ssh]: https://gitlab.hzdr.de/help/user/ssh.md#see-if-you-have-an-existing-ssh-key-pair
+[create-ssh]: https://gitlab.hzdr.de/help/user/ssh.md#generate-an-ssh-key-pair
+[add-ssh]: https://gitlab.hzdr.de/help/user/ssh.md#add-an-ssh-key-to-your-gitlab-account
+[verify-ssh]: https://gitlab.hzdr.de/help/user/ssh.md#verify-that-you-can-connect