[Docs] optimize and supplement docs system (#86)

Signed-off-by: Gaohan123 <gaohan19@huawei.com>

docs/cli/README.md

@@ -0,0 +1,24 @@
+# vLLM-Omni CLI Guide
+
+The CLI for vLLM-Omni inherits from vllm with some additional arguments.
+
+## serve
+
+Starts the vLLM-Omni OpenAI Compatible API server.
+
+Start with a model:
+
+```bash
+vllm serve Qwen/Qwen2.5-Omni-7B --omni
+```
+
+Specify the port:
+
+```bash
+vllm serve Qwen/Qwen2.5-Omni-7B --omni --port 8091
+```
+
+If you have custom stage configs file, launch the server with command below
+```bash
+vllm serve Qwen/Qwen2.5-Omni-7B --omni --stage-configs-path /path/to/stage_configs_file
+```