add forward declaration examples

add class & inheritance examples

CPlusPlus/Classes/Entity.cpp

@@ -0,0 +1,16 @@
+#include "Entity.h"
+
+Entity::Entity()
+{
+
+}
+
+Entity::Entity(std::string name) : name(name)
+{
+	//this->name = name;
+}
+
+std::string Entity::ToString()
+{
+	return name;
+}