Using pane_grid with screen percentages.

[madelaney]

I was looking at the pane_grid example, and I was curious if the pane_grid supported something that allowed me to split the screen into chunks based on percentages. For example, If I wanted to split the main window into something like this screenshot:

Where Panel A, Panel B, and Panel D are 10% of the screen and Panel C is the remainder of the screen.