This PR adds a model card for FLUID-7B, which includes:
- Metadata for `pipeline_tag: text-generation` and `library_name: transformers`.
- Links to the paper "From AR to Diffusion: Efficiently Adapting Large Language Models with Strictly Causal and Elastic Horizons".
- A link to the official GitHub repository.
- A summary of the key features: Strictly Causal Alignment and Elastic Horizon Modeling.
- A performance table showing benchmark results on MMLU, GSM8K, MATH500, and HumanEval.
- The bibtex citation for the paper.
