So, make your own JSON-like format. It's not like it'll be hard to understand, parse, or output. Comments are lines whose first non-whitespace character is a #. Allow keys to not need double-quotes. Allow commas before closed parens. Make a beautifier for your format that puts returns, tabs, spaces where you think they should go.

I'm just going to highlight - you want to use it as a configuration format, right? So do it! What on earth is stopping you?