Consider using YAML for output.json

[Gallaecio]

While it has its own issues, YAML could be a better format for a file that is meant to be read and edited by humans.

I’m thinking specifically of being able to write long strings, or even leave comments.

[lopuhin]

Perhaps JSON5 can be another option, it's backwards compatible with JSON, also allows comments and other extra features, and also solves a problem with YAML that you can't easily copy-paste stuff there if it's some complex value, like a list of objects.

[Gallaecio]

I don’t have a strong opinion about YAML, but whatever we choose, we should be able to edit the file contents with minimal changes to the existing, user-defined content (round-trip editing?). I know ruamel.yaml supports that, I don’t know if there is a Python json5 library that does (the changelog of https://pypi.org/project/json5/ mentions it as a 2.0 feature, they are at 0.12).