Missing link / tutorial page : Advanced_ssh_usage.md

[evezeyl]

At the end of this tutorial: https://github.com/NorwegianVeterinaryInstitute/nvi-documentation/blob/main/docs/source/technical/sagalogin.md
is a link refereing to this file Advanced_ssh_usage.md broken or abscent.

Either replace by SIGMA2 ssh connection or find / create the missing information

NB: acctually a good session on SSH keys

• including setting up in SAGA
• manager and configuration in GIT (eg. ssh config file to use different keys)
• and evt more advanced settings (recalling something for george)
  would be a nice session ...

George/Novicha added in the loop for info

[evezeyl]

(and maybe need to learn which tags to use on github Eve ! )