Added sample for VK_EXT_descriptor_buffer

Work-in-progress

data/shaders/glsl/descriptorbuffer/cube.frag

@@ -0,0 +1,14 @@
+#version 450
+
+layout (set = 2, binding = 0) uniform sampler2D samplerColorMap;
+
+layout (location = 0) in vec3 inNormal;
+layout (location = 1) in vec3 inColor;
+layout (location = 2) in vec2 inUV;
+
+layout (location = 0) out vec4 outFragColor;
+
+void main() 
+{
+	outFragColor = texture(samplerColorMap, inUV) * vec4(inColor, 1.0);
+}