updating sbt record data example to also cover miss sbt data

data/shaders/glsl/raytracingsbtdata/miss.rmiss

@@ -3,7 +3,15 @@
 
 layout(location = 0) rayPayloadInEXT vec3 hitValue;
 
+layout(shaderRecordEXT, std430) buffer SBT {
+  float r;
+  float g;
+  float b;
+};
+
 void main()
 {
-    // for now, we do nothing in the miss program
+  // Update the hit value to the hit record SBT data associated with this 
+  // miss record
+  hitValue = vec3(r, g, b);
 }