Minor adjustment to simpledom example

Showing the type Value and preventing member lookup twice.

example/simpledom/simpledom.cpp

@@ -15,7 +15,8 @@ int main() {
 	d.Parse<0>(json);
 
 	// 2. Modify it by DOM.
-	d["stars"].SetInt(d["stars"].GetInt() + 1);
+	Value& s = d["stars"];
+	s.SetInt(s.GetInt() + 1);
 
 	// 3. Stringify the DOM
 	StringBuffer buffer;