So I'm new to swagger and just trying to wrap my head around it and have a question about the swagger yml file. I see that you can write you're own swagger yml file, but if you have a API built in node/express already, can swagger just generate that file for you based on the node/express code? Not looking for code here, but just someone to point me in the right direction or help me understand this a bit more. I did a bunch of reading online and watching youtube vidoes, but still wasn't quite sure.