Configuring cursor:hide_on_key_press on a per window basis

[IsaiahPaget]

Hello there,

I am currently building a game and I noticed that my cursor would disappear when I start typing which is really great, and I want that behaviour for like 99% of things I do, but when I am playing my game I don't want my cursor to disappear. My first thought was to add some sort of extra config that allows you to set the hide_on_key_press for a window based on it's class. But then after doing some looking around it seems like maybe it would be better as a windowrule.

Let me know what y'all think, I'd be happy to make the PR for it too!