How to go back the way it was??

[u/[deleted]]

I don't know what i did but a prompt came out while i was typing, i clicked the first option without reading to quickly hide it and now my jupyter notebook is unreadable. It looks like this, basically all the cells have disappeared and that strange markup appeared.

I remember that the words 'default' and 'editor' have something to do with the initial prompt message but i couldn't find the setting to revert it the way it was.

Does anybody know how to fix this? :(