Correct pipeline tag to text-to-3d

This PR corrects the `pipeline_tag` to `text-to-3d` to better reflect the model's capabilities, making it more discoverable for users searching for text-to-3D generation models. The model also supports image-to-3D, but `text-to-3d` is a more precise primary pipeline tag given the emphasis in the README and the provided code example.

README.md

@@ -1,17 +1,18 @@
 ---
+language:
+- en
+- zh
 library_name: hunyuan3d-2
 license: other
 license_name: tencent-hunyuan-community
 license_link: https://huggingface.co/tencent/Hunyuan3D-2/blob/main/LICENSE.txt
-language:
-  - en
-  - zh
+pipeline_tag: text-to-3d
 tags:
-  - image-to-3d
-  - text-to-3d
-pipeline_tag: image-to-3d
+- image-to-3d
+- text-to-3d
 ---
 
+```markdown
 <p align="center">
   <img src="https://huggingface.co/tencent/Hunyuan3D-2/resolve/main/assets/images/teaser.jpg">
 </p>
@@ -104,4 +105,4 @@ Thanks for the contributions of community members, here we have these great exte
 We would like to thank the contributors to
 the [DINOv2](https://github.com/facebookresearch/dinov2), [Stable Diffusion](https://github.com/Stability-AI/stablediffusion), [FLUX](https://github.com/black-forest-labs/flux), [diffusers](https://github.com/huggingface/diffusers)
 and [HuggingFace](https://huggingface.co) repositories, for their open research and exploration.
-
+```