Sylvia/docs/doc 759

@jmclaus Hey Jean-Michel - I can't get this to work. When I create the component in my toy course, there's just a big blank box where the molecule should be. Can you look through this and let me know if some of the instructions are wrong? Thanks!
maybe move this above the heading, as a sentence rather than a note? it seems more like a general prerequisite than a quick "oh by the way" before starting the steps...