[Doc] Create a new "Usage" section (#10827)

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

docs/source/models/supported_models.rst

@@ -471,6 +471,8 @@ Sentence Pair Scoring
 .. note::
     These models are supported in both offline and online inference via Score API.
 
+.. _supported_mm_models:
+
 Multimodal Language Models
 ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
@@ -489,8 +491,6 @@ On the other hand, modalities separated by :code:`/` are mutually exclusive.
 
 - e.g.: :code:`T / I` means that the model supports text-only and image-only inputs, but not text-with-image inputs.
 
-.. _supported_vlms:
-
 Text Generation
 ---------------
 
@@ -646,6 +646,21 @@ Text Generation
 | :sup:`E` Pre-computed embeddings can be inputted for this modality.
 | :sup:`+` Multiple items can be inputted per text prompt for this modality.
 
+.. important::
+    To enable multiple multi-modal items per text prompt, you have to set :code:`limit_mm_per_prompt` (offline inference)
+    or :code:`--limit-mm-per-prompt` (online inference). For example, to enable passing up to 4 images per text prompt:
+
+    .. code-block:: python
+
+        llm = LLM(
+            model="Qwen/Qwen2-VL-7B-Instruct",
+            limit_mm_per_prompt={"image": 4},
+        )
+
+    .. code-block:: bash
+
+        vllm serve Qwen/Qwen2-VL-7B-Instruct --limit-mm-per-prompt image=4
+
 .. note::
   vLLM currently only supports adding LoRA to the language backbone of multimodal models.