This PR enhances the model card by:
- Adding the `pipeline_tag: depth-estimation` to the metadata, which improves discoverability on the Hugging Face Hub (https://huggingface.co/models?pipeline_tag=depth-estimation).
- Including the paper abstract for better understanding of the model's context and contributions.
- Providing a clear sample usage code snippet from the GitHub README for Camera Depth Models (CDM), making it easier for users to get started.
- Consolidating and explicitly linking to the Hugging Face paper page, the project page, and the main GitHub repository for comprehensive information.
- Adding the citation information from the paper.
