using for instead of For in descriptions; maybe there is a pedagogic reason to prefer "For" but given that the Python syntax is lowercase and we have it in backticks this seems clearer.
adding a link for SSSP data. If we end up having this preinstalled or in some other setup instructions it can come out again. But I think this will make the tutorial more useful for people not at our workshop, either way.
Some more small stuff
forinstead ofForin descriptions; maybe there is a pedagogic reason to prefer "For" but given that the Python syntax is lowercase and we have it in backticks this seems clearer.