Conflicts:
- `CONTRIBUTING.md`:
Upstream file has changed and we're quoting it.
Ported the changes.
- `README.md`:
Upstream file has changed but we have a completely different one.
Kept our version.
- `lib/mastodon/version.rb`:
Upstream has changed from `tootsuite/mastodon` to `mastodon/mastodon`,
but we're still `glitch-soc/mastodon`.
Kept our version.
- `spec/presenters/instance_presenter_spec.rb`:
Upstream has changed from `tootsuite/mastodon` to `mastodon/mastodon`,
but we're still `glitch-soc/mastodon`.
Kept our version.