Another possible convention from the npm world:

```
{ "//": "this is the first line of a comment", 
  "//": "this is the second line of the comment" } 

{ "//": [ 
  "first line", 
  "second line" ] } 
```

My hesitation about JSON for config is that comments in JSON will always be controversial. Any convention will be a barrier for usage.

What you implemented is the cleanest looking of the conventions and the most pleasant to me, but it's going to bug the JSON purists. But I'm going to ponder it a bit more.