SSH section update

[ktiits]

SSH is connection standard, not program, similar to S3 and then several tools supporting it. SSh keys are not required in Puhti/Mahti.

[samumantha]

The previous materials were just copied from some other slides without any updates. Except for the "have to", this was my misinformation.
I disagree with removing ssh key setup, reasons highlighted in below text.
They could at least be in hidden box?
From docs: "For now, SSH access to Puhti/Mahti can be authenticated using the password of your CSC user account, but for increased security (and convenience) you should set up SSH keys as your primary method for authentication."

I removed the web interface and added the SSH keys sentence and link, but likely clicked something wrong here.. So pushing the dismiss button, to get further..