@Helikopter
UPD2:
Okay, I figured out 2 and 4 problems, it’s all about headers hierarchy. For example, # is the main header folds everything beneath until I put another # header.
I have a little problem slightly out of a topic, but I don’t want to create another post:
Is it possible to start new line slightly indented? If I understood correctly, it’s possible with TAB in the code block. But I need a raw line like new lines in the books.