Emulator of GUI

Hey! I was thinking about virtual emulator of GUI to have a reference how the interface looks and works. It could be as additional page on the wiki. Sound is not necessary there, just to spend some time to understand the workflow.

We used to have it many years ago. An online version of the GUI, just for people to try it out.

Turns out this is not so simple to maintain, but it is a good idea indeed!