[Docs] Add comprehensive CLI reference for all large vllm subcommands (#22601)

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

vllm/entrypoints/openai/run_batch.py

@@ -20,7 +20,6 @@ from vllm.engine.arg_utils import AsyncEngineArgs, optional_type
 from vllm.engine.protocol import EngineClient
 from vllm.entrypoints.logger import RequestLogger
 # yapf: disable
-from vllm.entrypoints.openai.api_server import build_async_engine_client
 from vllm.entrypoints.openai.protocol import (BatchRequestInput,
                                               BatchRequestOutput,
                                               BatchResponseData,
@@ -34,7 +33,6 @@ from vllm.entrypoints.openai.serving_models import (BaseModelPath,
                                                     OpenAIServingModels)
 from vllm.entrypoints.openai.serving_score import ServingScores
 from vllm.logger import init_logger
-from vllm.usage.usage_lib import UsageContext
 from vllm.utils import FlexibleArgumentParser, random_uuid
 from vllm.version import __version__ as VLLM_VERSION
 
@@ -469,6 +467,9 @@ async def run_batch(
 
 
 async def main(args: Namespace):
+    from vllm.entrypoints.openai.api_server import build_async_engine_client
+    from vllm.usage.usage_lib import UsageContext
+
     async with build_async_engine_client(
             args,
             usage_context=UsageContext.OPENAI_BATCH_RUNNER,