Streaming use case: add display to show what's being recorded/streamed

See https://forum.videolan.org/viewtopic.php?f=14&t=159796&p=527247

To be added probably in https://docs.videolan.me/vlc-user/3.0/en/advanced/streaming/

added Beginner friendly label

Hi @alexandre-janniaux, I'll like to be assigned this task. A nice place to tuck it in would be just above the Save the file locally subheading just underneath the Introduction to the standard output module.

Please do it. :D

Alright, on it.

mentioned in merge request !69 (closed)