[docs] Model docs

[stevhliu]

🚧 WIP 🚧

Explores a new design for several of the most commonly visited model docs. It is pretty stripped down at the moment, but we can add back the essentials as needed (or not). The main idea is to only show developers what they need to know to use the model.

• A badge indicating whether a model supports certain features/frameworks (PyTorch, SDPA, FlashAttention, etc.) in the upper right side of the doc.
• A brief description of the model and what makes it different. Some of these abstracts just don't tell you that much about the model itself or what makes it unique, while others are very technical and the details probably don't matter that much if you aren't a researcher. The description aims for somewhere in between.
• Code snippets demonstrating inference with all the optimizations included.

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.