[REF-1072] Add more layout examples to the docs

[masenf]

The docs should have more examples on how to layout the root of the page for those less familiar with css/flexbox or who just want to get started more quickly by picking a layout visually and getting the code for it.

Based on #2100

_REF-1072

[include]

In fact this is what is pushing me back - lack of time/motivation to "design" initial layout. people like us would benefit a lot with this presets.

[picklelo]

We now have a layout overview and are working on recipes to make the UI/layout aspects easier.