GPD Win 4 back buttons.

[this-is-just-con-tribute]

So I finally made them, and I made sure the layers weren't grouped in case y'all thought they needed to be adjusted. Here are the individual button files. I must admit the most challenging part was making them not appear too big compared to the rest of the prompts. Since all of them use the same size letters, I didn't touch the sizing for consistency's sake. Idk if that's gonna have any unforeseen effects, like making it look smaller compared to everything else, or bigger. Hopefully it won't. Thanks again for the opportunity to contribute to this amazing project.