These comments should attach to other nodes so that they can be preserved in the AST and produced by the compiler later.
For example, adding a comment to a property will always apply to it and display it when that property is queried for an explanation. These comments are a kind of documentation, but they could also be storytelling. They may be attached to an event. There may even be a 'storytelling mode' which walks through the changes a character has had using these comments.
I'm not sure how these should look yet, so they need designing.