Brightness slider for discord screen sharing.

A brightness slider can fix multiple problems with the screen sharing. Problems I can see getting fixed are Dark games being very hard to watch due to differing brightness settings on host's and watcher's monitors and the HDR bug where the brightness is incredibly high and pretty much unwatchable (but is somehow fixed due to alt-tabbing off the HDR monitor and program.) Games that i know are hard to watch when streaming are games like escape from tarkov, marauders, Hunt: Showdown (specifically indoors), Back 4 Blood, and many others.