text: Title: Support for frozen dataclasses
  Body: **Is your feature request related to a problem? Please describe.**
  Not really a problem per say. But many of our current models are frozen dataclasses. We try to keep them immutable by default. But unfortunately theres not a flag for it when generating through this tool. 
  
  We will probably still explore generating these just as not frozen to start, so not really a blocker. But it would be awesome if we could bring that in soon.
  
  **Describe the solution you'd like**
  It seems like it would be straightforward to utilize the already available `--enable-faux-immutability` flag.
  
  **Describe alternatives you've considered**
  Could add another flag of `--frozen-dataclasses` or similar. 
  
  **Additional context**
  Nothin that I can think of. If I have time I will try to get a PR up if desired :)