Make Container collabsible

[criwe]

Hi!

to have more clarity in the backend, it would be great if the containers were expandable/collapsible
There is an extension (https://github.com/evoWeb/ew_collapsible_container/), but imho such a function should be integrated directly, as it is essential for the usability and clarity.

Many greetings,
Christoph

[chesio]

Hi @criwe, this has already been requested before: #123

[criwe]

Oh, thanks! I´ll close that one.