Add doc about "lite display" mode

[matks]

I want to write documentation about the lite display mode that will be enabled in SF pages with PR https://github.com/PrestaShop/PrestaShop/pull/12897.

I'm wondering how do I write it 🤔. In some "layout features" part ? In "what you can do with BO pages" part ? Where would it belong ?

I also thought maybe we could write doc about any BO (and soon FO) page that has some trick in it. So if I follow this idea, it would be a "Order page insights" part where we would explain how this page is different from the other, what kind of code is related to it, and the "lite display" mode being used there.