Support folding or hiding cells

[amabdallah]

Could you please consider adding a functionality to support folding or hiding cells especially the ones with long scripts?

I see different methods to do it but I was wondering if you could do it at your end.
It would be nice to store the setting for whatever cells are folded or not at the time of publishing it.

The notebook will be then more manageable and users could unfold cells to see more details about them if interested.