Move dockerfiles into their own directory (#14549)

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

vllm/config.py

@@ -317,8 +317,8 @@ class ModelConfig:
             ) and backend == "FLASHINFER" and find_spec("flashinfer") is None:
             raise ValueError(
                 "VLLM_ATTENTION_BACKEND is set to FLASHINFER, but flashinfer "
-                "module was not found."
-                "See https://github.com/vllm-project/vllm/blob/main/Dockerfile "
+                "module was not found. See "
+                "https://github.com/vllm-project/vllm/blob/main/docker/Dockerfile "  # noqa: E501
                 "for instructions on how to install it.")
 
         # The tokenizer version is consistent with the model version by default.