Remember the state of the sidebar

Hey, I have been using alligator on my desktop and think it is great for my needs. One thing I noticed is that the side bar doesn't remember it's position on startup. I find myself collapsing it every time I open it, so that whatever article I am reading can have more space. Anyways, I thought why don't I try my hand at fixing it, so here we are. Let me know if this looks good and if it is something you would accept.