If its a config file I'm not sure why you'll need comments. Comments / documentation should be in the system you'll do the config for. If your set options are that quirky / need documentation; why not explain them in a README?
But maybe I misunderstood. Can you give an example of a comment that makes sense / is required in a configuration JSON?
> If your set options are that quirky / need documentation; why not explain them in a README?
Mostly because I don't know whether the person customizing my code will read the README, but they'll definitely see the comments I wrote right before the configuration option itself.
With comments and some extra whitespace, they can go through the file line by line, read what a specific option does, configure it properly, and move on to the next one. No back and forth to the README required.
But maybe I misunderstood. Can you give an example of a comment that makes sense / is required in a configuration JSON?