Add url to examples

examples/07-callback/callback.cpp

@@ -307,8 +307,8 @@ private:
 class ExampleCallback : public entry::AppI
 {
 public:
-	ExampleCallback(const char* _name, const char* _description)
-		: entry::AppI(_name, _description)
+    ExampleCallback(const char* _name, const char* _description, const char* _url)
+        : entry::AppI(_name, _description, _url)
 	{
 	}
 
@@ -498,4 +498,9 @@ public:
 
 } // namespace
 
-ENTRY_IMPLEMENT_MAIN(ExampleCallback, "07-callback", "Implementing application specific callbacks for taking screen shots, caching OpenGL binary shaders, and video capture.");
+ENTRY_IMPLEMENT_MAIN(
+    ExampleCallback
+    , "07-callback"
+    , "Implementing application specific callbacks for taking screen shots, caching OpenGL binary shaders, and video capture."
+    , "https://bkaradzic.github.io/bgfx/examples.html#callback"
+    );