feedback from CarpentryConnect 2019 to improve material

[annefou]

I got very good tips on how to improve material:

nicer way to format the html string (without having to add + signs and loads of """ etc):
html = """

Instructors: {}

""".format(" ".join(instructors))

also if want to avoid for i in range(0, len(list)) can use for element in list, which iterates through list elements, eg 
for element in features:
    location = (element['geometry']['coordinates'][1],element['geometry']['coordinates'][0])