chore: import upstream snapshot with attribution

samples/cpp/tutorial_code/introduction/documentation/documentation.cpp

@@ -0,0 +1,14 @@
+#include <iostream>
+
+/**
+ * @function main
+ * @brief Main function
+ */
+int main( void )
+{
+    //! [hello_world]
+    std::cout << "Hello World!";
+    //! [hello_world]
+
+    return 0;
+}