community[docs]: Add content for the Lora adapter in the VLLM page. (#27788)

**Description:**
I added code for lora_request in the community package, but I forgot to
add content to the VLLM page. So, I will do that now. #27731

---------

Co-authored-by: Um Changyong <changyong.um@sfa.co.kr>

docs/docs/integrations/llms/vllm.ipynb

@@ -246,6 +246,35 @@
     ")\n",
     "print(llm.invoke(\"Rome is\"))"
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "bd3f0f51",
+   "metadata": {},
+   "source": [
+    "## LoRA adapter\n",
+    "LoRA adapters can be used with any vLLM model that implements `SupportsLoRA`."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "2682ca6c",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from langchain_community.llms import VLLM\n",
+    "from vllm.lora.request import LoRARequest\n",
+    "\n",
+    "llm = VLLM(model=\"meta-llama/Llama-2-7b-hf\", enable_lora=True)\n",
+    "\n",
+    "LoRA_ADAPTER_PATH = \"path/to/adapter\"\n",
+    "lora_adapter = LoRARequest(\"lora_adapter\", 1, LoRA_ADAPTER_PATH)\n",
+    "\n",
+    "print(\n",
+    "    llm.invoke(\"What are some popular Korean street foods?\", lora_request=lora_adapter)\n",
+    ")"
+   ]
   }
  ],
  "metadata": {