Serialize comments

[flaviojs]

I have a json config file that has comments.
It is meant to be edited manually or with a GUI launcher.

Ideally there would be a way to roundtrip the comments in the launcher with rust but I can't find anything.

The minimum I need is a way to serialize default comments.
Maybe something like:

#[derive(Deserialize, Debug, Serialize)]
struct Config {
    #[json5(default_comment = "Number of milliseconds for one game cycle. Default: 25")]
    ms_per_game_cycle: i32,
}

would be serialized into something like:

{
  // Number of milliseconds for one game cycle. Default: 25
  "ms_per_game_cycle": 25
}