GPU: small xbr doc update

runelite-client/src/main/java/net/runelite/client/plugins/gpu/config/UIScalingMode.java

@@ -35,7 +35,7 @@ public enum UIScalingMode
 	LINEAR("Bilinear", 0),
 	MITCHELL("Bicubic (Mitchell)", 1),
 	CATMULL_ROM("Bicubic (Catmull-Rom)", 2),
-	XBR("XBR (best at 2x & above)", 3);
+	XBR("xBR (best at 2x & above)", 3);
 
 	private final String name;
 	private final int mode;

runelite-client/src/main/resources/net/runelite/client/plugins/gpu/scale/xbr_lv2_frag.glsl

@@ -104,6 +104,9 @@ float c_df(vec3 c1, vec3 c2)
 
 #include scale/xbr_lv2_common.glsl
 
+
+// xBR-level2 upscaler. Level 2 means it detects edges in 2 directions, instead of just 1 in the most basic form of the algorithm.
+// This improves quality by a good bit without adding too much complexity compared to available level-3 and level-4 algorithms.
 vec4 textureXBR(sampler2D image, vec2 texCoord, XBRTable t, float scale)
 {
     vec4 delta   = vec4(1.0/scale, 1.0/scale, 1.0/scale, 1.0/scale);