Sorry, I'm a newbie with Jupyter (on chrome, Linux),
but I run into a problem:
due to my inexperience, I often made this mistake: after inserting a new line (above or below: A or B) I start writing immediately, believing that I'm already inside the cell, and not still in (I think it's called) command mode...
Needless to say, doing this I inserted a lot of commands without intention.
Last time it happened, I noticed that 1) my notebooks are not tabbed anymore, and 2) my left sidebar (files, running, commands...) disappeared.
I thought I entered without wanting into single document mode, but ctrl-shift-enter does nothing.
Can you help me please?
Alessandro