[Docs] Update README supported models section with TTS and Diffusion categories (#4300)

Signed-off-by: hsliu_ustc <hsliu_ustc@noreply.gitcode.com>
Co-authored-by: hsliu_ustc <hsliu_ustc@noreply.gitcode.com>
Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

README.md

@@ -57,8 +57,9 @@ vLLM-Omni is flexible and easy to use with:
 
 vLLM-Omni seamlessly supports most popular open-source models on HuggingFace, including:
 
-- Omni-modality models (e.g. Qwen-Omni)
-- Multi-modality generation models (e.g. Qwen-Image)
+- **Omni-modality models** (e.g. Qwen3-Omni, Cosmos, HunyuanImage, BAGEL)
+- **TTS models** (e.g. Qwen3-TTS, VoxCPM2, Ming-Omni-TTS, CosyVoice3)
+- **Diffusion models** — image, video, and audio generation (e.g. Qwen-Image, Wan2.2, FLUX)
 
 ## Getting Started