Add Switzerland to the list

[loleg]

We have been semi-maintaining a project (one update every 8 years or so.. 😋), and have today made a small update to it. Basically there is a simple API now we can use to refresh the Swiss public bodies data. See OpendataCH/public_bodies_of_the_swiss_federation#1

[rufuspollock]

@loleg do you want to open a pull request to put the swiss data in?