Update README.md

We need to import torch

README.md

@@ -35,6 +35,7 @@ Please make sure to either disable `guidance_scale` or use values between 1.0 an
 
 ```python
 from diffusers import UNet2DConditionModel, DiffusionPipeline, LCMScheduler
+import torch
 
 unet = UNet2DConditionModel.from_pretrained("latent-consistency/lcm-sdxl", torch_dtype=torch.float16, variant="fp16")
 pipe = DiffusionPipeline.from_pretrained("stabilityai/stable-diffusion-xl-base-1.0", unet=unet, torch_dtype=torch.float16, variant="fp16")