readme: ```
  from diffusers import StableDiffusionPipeline
  import torch
  
  model_id = "carpedm20/test"
  pipe = StableDiffusionPipeline.from_pretrained(model_id, torch_dtype=torch.float16)
  pipe = pipe.to("cuda")
  
  prompt = "a photo of an astronaut riding a horse on mars"
  image = pipe(prompt).images[0]  
      
  image.save("astronaut_rides_horse.png")
  ```