implement billboard shader and add new example

openVulkanoCpp/Shader/billboardFromSinglePoint.vert

@@ -0,0 +1,35 @@
+#version 450
+
+layout(location = 0) in vec3 pos;
+layout(location = 1) in vec3 normal;
+layout(location = 5) in vec4 color;
+
+layout(location = 0) out VS_OUT {
+    vec4 color;
+} vs_out;
+
+layout(set = 0, binding = 0) uniform NodeData
+{
+	mat4 world;
+} node;
+
+layout(set = 1, binding = 0) uniform CameraData
+{
+    mat4 viewProjection;
+    mat4 view;
+    mat4 projection;
+    vec4 camPos;
+} cam;
+
+layout(set = 2, binding = 0) uniform BillboardData
+{
+   vec2 size;
+   vec2 windowSize;
+   bool isFixedSize;
+} billboardInfo;
+
+void main() {
+	// single point
+	gl_Position = node.world * vec4(pos, 1);
+    vs_out.color = color;
+}