For those wanting human readable and editable configuration files, NestedText might be a solution. It only supports strings, but conversions can be done during import anyway.

https://nestedtext.org/en/latest/

NestedText already is the way I use YAML; everything is intepreted as a string. I have some trust in my YAML parser to not mangle most strings. I could use NestedText, but users would be unfamiliar with it, and IIRC the only parsers are in Python. But then I could use StrictYaml too https://github.com/crdoconnor/strictyaml