Demo/DeferredShading: Add tone-mapping (without automatic exposure for now)

bin/resources/bloom_bright.nzsl

@@ -54,7 +54,7 @@ fn main(input: FragIn) -> FragOut
 	color /= vec3<f32>(1.0, 1.0, 1.0) + color;
 
 	let output: FragOut;
-	output.color = vec4<f32>(color, 1.0);
+	output.color = vec4<f32>(max(color, vec3<f32>(0.0, 0.0, 0.0)), 1.0);
 
 	return output;
 }