SSH 2-Factor's First Factor (Raspberry Pi/Linux Tutorial)

Hey all. I've been trying for some years now to be more proactive in posting beginner-friendly tutorials for some of the things I've felt are less accessible in my field.

This is part 2 of a 2 part tutorial showing how to enable TOTP and SSH keys (instead of passwords) on Raspberry Pi and Linux in general.

I've tried to balance between explaining thoroughly for those that wish to learn and a concise tutorial that can be skipped to for those who don't.

Feedback on the style and content would be appreciated. Issues can be raised on GitHub (link is on the blog).