Make Staged Files window resizable instead of splitting 50/50 with Unstaged.

Please make Staged Files window resizable instead of splitting 50/50 with Unstaged Files window. I normally find myself in situations where I have a lot of unstaged files and need to stage 1 or 2 only for the next commit, so I would naturally want to make the unstaged window smaller and give more display space to unstaged to see more files and easier scroll through.