reading_writing_json_6 does not contain images/

There is a mistake where _reading_writing_json_5/_ contains the _images/_ folder but it's in _reading_writing_json_6/_ that they are actually being used. I tried to submit a PR but I think push rights are not permitted 😄 

So it should be
```bash
mv reading_writing_json_5/images reading_writing_json_6
```