Check in hello world example so it stays up to date

samples/samples.gyp

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 44 matching lines @@
     ],
   },
   'targets': [
     {
       'target_name': 'shell',
       'sources': [
         'shell.cc',
       ],
     },
     {
+      'target_name': 'hello-world',
+      'sources': [
+        'hello-world.cc',
+      ],
+    },
+    {
       'target_name': 'process',
       'sources': [
         'process.cc',
       ],
     },
   ],
 }