Window pane with window sill

[Lithembia]

I would like to have a window pane with a sill inside (or outside, you could rotate it) that I can place something on, like a cool rock or a flower pot. It would be like a shelf with only the front two shelf spaces open. Maybe to avoid floating objects if the block below isn't a full block you could have the window block have a wooden sill on the bottom so the items have something to sit on. 

[Nathan Flaminio]

There's a mod that works great for that

https://mods.vintagestory.at/windowstorage