Migrate docs from Sphinx to MkDocs (#18145)

Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

docs/serving/integrations/llamaindex.md

@@ -0,0 +1,27 @@
+---
+title: LlamaIndex
+---
+[](){ #serving-llamaindex }
+
+vLLM is also available via [LlamaIndex](https://github.com/run-llama/llama_index) .
+
+To install LlamaIndex, run
+
+```console
+pip install llama-index-llms-vllm -q
+```
+
+To run inference on a single or multiple GPUs, use `Vllm` class from `llamaindex`.
+
+```python
+from llama_index.llms.vllm import Vllm
+
+llm = Vllm(
+    model="microsoft/Orca-2-7b",
+    tensor_parallel_size=4,
+    max_new_tokens=100,
+    vllm_kwargs={"swap_space": 1, "gpu_memory_utilization": 0.5},
+)
+```
+
+Please refer to this [Tutorial](https://docs.llamaindex.ai/en/latest/examples/llm/vllm/) for more details.