[Doc] Expand Multimodal API Reference (#11852)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>

docs/source/api/multimodal/index.md

@@ -2,10 +2,6 @@
 
 # Multi-Modality
 
-```{eval-rst}
-.. currentmodule:: vllm.multimodal
-```
-
 vLLM provides experimental support for multi-modal models through the {mod}`vllm.multimodal` package.
 
 Multi-modal inputs can be passed alongside text and token prompts to [supported models](#supported-mm-models)
@@ -13,61 +9,20 @@ via the `multi_modal_data` field in {class}`vllm.inputs.PromptType`.
 
 Looking to add your own multi-modal model? Please follow the instructions listed [here](#enabling-multimodal-inputs).
 
-
 ## Module Contents
 
-```{eval-rst}
-.. automodule:: vllm.multimodal
-```
-
-### Registry
-
 ```{eval-rst}
 .. autodata:: vllm.multimodal.MULTIMODAL_REGISTRY
 ```
 
-```{eval-rst}
-.. autoclass:: vllm.multimodal.MultiModalRegistry
-    :members:
-    :show-inheritance:
-```
-
-### Base Classes
-
-```{eval-rst}
-.. automodule:: vllm.multimodal.base
-    :members:
-    :show-inheritance:
-```
-
-### Input Classes
-
-```{eval-rst}
-.. automodule:: vllm.multimodal.inputs
-    :members:
-    :show-inheritance:
-```
-
-### Audio Classes
-
-```{eval-rst}
-.. automodule:: vllm.multimodal.audio
-    :members:
-    :show-inheritance:
-```
-
-### Image Classes
-
-```{eval-rst}
-.. automodule:: vllm.multimodal.image
-    :members:
-    :show-inheritance:
-```
-
-### Video Classes
-
-```{eval-rst}
-.. automodule:: vllm.multimodal.video
-    :members:
-    :show-inheritance:
+## Submodules
+
+```{toctree}
+:maxdepth: 1
+
+inputs
+parse
+processing
+profiling
+registry
 ```