Add pipeline tag and library name, add sample usage

This PR improves the model card by:
- Adding the `pipeline_tag: text-to-image` to enhance discoverability on the Hugging Face Hub.
- Adding the `library_name: diffusers` to enable the automated code snippet for `diffusers`.
- Including a Python sample usage snippet directly from the GitHub README for text-to-image generation.

README.md

@@ -1,5 +1,7 @@
 ---
 license: cc-by-nc-nd-4.0
+library_name: diffusers
+pipeline_tag: text-to-image
 ---
 
 # RealCustom Series
@@ -37,7 +39,36 @@ bash inference/inference_single_image.sh
 python inference/app.py
 ```
 
-##  Citation
+### Sample Usage (Text-to-Image Generation)
+
+```python
+from inference_solver import FlexARInferenceSolver
+from PIL import Image
+
+# ******************** Image Generation ********************
+inference_solver = FlexARInferenceSolver(
+    model_path="Alpha-VLLM/Lumina-mGPT-7B-768",
+    precision="bf16",
+    target_size=768,
+)
+
+q1 = f"Generate an image of 768x768 according to the following prompt:
+"
+     f"Image of a dog playing water, and a waterfall is in the background."
+
+# generated: tuple of (generated response, list of generated images)
+generated = inference_solver.generate(
+    images=[],
+    qas=[[q1, None]],
+    max_gen_len=8192,
+    temperature=1.0,
+    logits_processor=inference_solver.create_logits_processor(cfg=4.0, image_top_k=2000),
+)
+
+a1, new_image = generated[0], generated[1][0]
+```
+
+## Citation
 If you find this project useful for your research, please consider citing our papers:
 ```bibtex
 @inproceedings{huang2024realcustom,