JSON comments format in module files

What is the significance of the below jswrapper connect section, with type = init. Although Event and static method definitions are pretty much fine.

I am not able to find much information but this Espruino documentation page

This part looks like comment only. But there is a nice script in the background, scanning for comments like this. As we can see, there is some data in JSON format. And this is translated into one more C-file. At the end, this generated file is the connection between Javascript file and the compiled C-function.
When and from where it will be called and

/*JSON{
  "type" : "init",
  "generate" : "jswrap_xxx_init"
}*/

EDIT: Similarly Type: kill/idle