RoboHelp has nothing specific to Articulate Storyline, but it should be able to work with the output and include it as part of a RoboHelp project.
I'm fairly new to Rh, but I can tell you that unlike Captivate, Articulate Storyline files require you to maintain the folder structure of the supporting files that accompany the story.htm file. Within the baggage files in Rh, you will need to make a sub-folder to support this. See the screenshot for details.
I had to play around with the formatting a bit, but in the WebHelpPro output, the Storyline elearning works great.
Best of luck,