Add new toggle to hide top header in Lovelace UI

Hello,

It would be great if a configuration toggle could be added to hide the top header in Lovelace UI.
There are many use cases where a user might wish to hide the top header to have a full-screen kiosk-like user interface.

Home assistant 0.117 has made a big step forward in this direction by making the header more compact and combining the original two rows into a single one. This was made possible thanks to the work done by @mayker (thanks for that!), who ported the code he initially wrote for the unofficial custom component “custom header” into Home Assistant Core.
He has then made another custom component called “Kiosk-mode” that allows to hide the top bar as well. However, I think this should be a built-in feature by Home Assistant.

I would suggest adding a toggle, right below the one that already allows to “Always hide the sidebar” in the user settings.

What do you think?

Actually, I’ve just realized that the Home Assistant Frontend repository on GitHub accepts new feature requests, so I’ve opened one: