Fix: Invalid import of SafetyChecker in example code

## Description

The example code in the model card fails with the following error:
```python
from transformers import AutoProcessor, SafetyChecker
# ImportError: cannot import name 'SafetyChecker' from 'transformers'
```

## Changes

Replaced:
```python
from transformers import AutoProcessor, SafetyChecker
```
with:
```python
from transformers import CLIPFeatureExtractor as AutoProcessor
from diffusers.pipelines.stable_diffusion.safety_checker import StableDiffusionSafetyChecker as SafetyChecker
```

## Testing
The code has been successfully tested and runs without error.

## Note
This contribution is part of an ongoing research initiative to systematically identify and correct faulty example code in Hugging Face Model Cards.
We would appreciate a timely review and integration of this patch to support code reliability and enhance reproducibility for downstream users.

README.md

@@ -174,7 +174,10 @@ Use the code below to get started with the model.
 <summary> Click to expand </summary>
 
 ```python
-from transformers import AutoProcessor, SafetyChecker
+#from transformers import AutoProcessor, SafetyChecker
+from transformers import CLIPFeatureExtractor as AutoProcessor
+from diffusers.pipelines.stable_diffusion.safety_checker import StableDiffusionSafetyChecker as SafetyChecker
+
 processor = AutoProcessor.from_pretrained("CompVis/stable-diffusion-safety-checker")
 safety_checker = SafetyChecker.from_pretrained("CompVis/stable-diffusion-safety-checker")
  ```