[Doc] Update Encoder-Decoder models support doc with Florence-2 (#34581)

Signed-off-by: Isotr0py <mozf@mail2.sysu.edu.cn>

docs/models/supported_models.md

@@ -181,6 +181,7 @@ Some model architectures are supported via vLLM plugins. These plugins extend vL
 | Architecture | Models | Plugin Repository |
 |--------------|--------|-------------------|
 | `BartForConditionalGeneration` | BART | [bart-plugin](https://github.com/vllm-project/bart-plugin) |
+| `Florence2ForConditionalGeneration` | Florence-2 | [bart-plugin](https://github.com/vllm-project/bart-plugin) |
 
 For other model architectures not natively supported, in particular for Encoder-Decoder models, we recommend following a similar pattern by implementing support through the plugin system.
 

docs/usage/v1_guide.md

@@ -137,6 +137,7 @@ Please note that prefix caching is not yet supported for any of the above models
 Whisper is supported natively. Other encoder-decoder models are supported via the plugin system:
 
 - **BART**: `BartForConditionalGeneration` is supported via the official [bart-plugin](https://github.com/vllm-project/bart-plugin).
+- **Florence-2**: `Florence2ForConditionalGeneration` is supported via the official [bart-plugin](https://github.com/vllm-project/bart-plugin).
 
 For other encoder-decoder models (e.g., `MllamaForConditionalGeneration`), we recommend
 following a similar pattern by implementing support through the [plugin system](../design/plugin_system.md).