Missing spec: Instance.world, instance, instance.n_users renamed to memberCount, missing /groups/:id/instances

[lillithrosepup]

Instance.world is either a world or a limitedworld, i cant tell
Instance.n_users has been renamed to Instance.memberCount as far as i can tell
/groups/:id/instances is missing from the spec entirely, returns either an instance or limitedinstance i havent checked

[Foorack]

@ttshivers Thank you very much for the contributions! Minor problem, while the endpoint was added, it is missing from main paths.yml, so the bundler is not including it when building the final spec. Could you please make a follow-up PR for this? ❤️

@ariesclark We should write a CI job which checks for all paths in any of the files inside paths/ are also included in the main paths.yml file. Generating the file automatically is possible but harder, as the order inside the file dictate the order on the website.