Image Upscaling via FSR or NIS for SteamVR games v2.0

This release adds NVIDIA's Image Scaling (NIS) as an alternative to AMD's FidelityFX SuperResolution (FSR). You can choose which algorithm you want to use by setting the new parameter useNIS in the config either to false (FSR, default) or true (NIS).

Both algorithms work similarly and take a similar amount of time, but the output is sufficiently different that it's worth experimenting which one you like better for a particular game.