Update README.md (#6191)

Typo: The script for LoRA training is `train_text_to_image_lora_prior.py` not `train_text_to_image_prior_lora.py`.

Alternatively you could rename the file and keep the README.md unchanged.

examples/wuerstchen/text_to_image/README.md

@@ -77,7 +77,7 @@ First, you need to set up your development environment as explained in the [inst
 ```bash
 export DATASET_NAME="lambdalabs/pokemon-blip-captions"
 
-accelerate launch train_text_to_image_prior_lora.py \
+accelerate launch train_text_to_image_lora_prior.py \
   --mixed_precision="fp16" \
   --dataset_name=$DATASET_NAME --caption_column="text" \
   --resolution=768 \