Add FSR support

Hi Facepunch,

Congrats on the recent DLSS adoption but that only helps people who already have fairly high powered graphics cards. It would be great if you also included FSR support which is supported on a broader and older range of graphics cards.

Currently, I am forced to play rust using nvidia GeForce now because my laptop (Surface book 2 with GTX 1060) can’t run Rust stable. I believe it could with upscaling.

Are you considering it? Thanks!