Nested rows in layout builder

[vtheod]

Hello @sonvnn

Because of a project I'm working on, I came up with an idea lately, but I don't know how easy it is to develop (I didn't have the time to check it).
I think it would be great if we had the option to create nested rows in astroid's layout builders

[sonvnn]

@vtheod Thanks for the suggestion. I have thought about this idea too. I will add it to my todo list in the future.