updating sbt record data example to also cover miss sbt data

data/shaders/hlsl/raytracingsbtdata/miss.rmiss

@@ -5,8 +5,18 @@ struct Payload
 [[vk::location(0)]] float3 hitValue;
 };
 
+struct SBT {
+  float r;
+  float g;
+  float b;
+};
+[[vk::shader_record_ext]]
+ConstantBuffer<SBT> sbt;
+
 [shader("miss")]
 void main(inout Payload p)
 {
-    // for now, we do nothing in the miss program
+  // Update the hit value to the hit record SBT data associated with this 
+  // miss record
+  p.hitValue = float3(sbt.r, sbt.g, sbt.g);
 }