docs: Fix Dockerfile path in README for vLLM dev image (#6429)

Signed-off-by: KrishnanPrash <140860868+KrishnanPrash@users.noreply.github.com>

container/README.md

@@ -227,7 +227,7 @@ Note: `uv` commands set `UV_CACHE_DIR` per `RUN` so `uv` always uses the same pa
 ```bash
 # Build vLLM dev image called dynamo:latest-vllm (default). This runs as root and is for development.
 python container/render.py --framework=vllm --target=dev --output-short-filename
-docker build -t dynamo:latest-vllm-dev -f rendered.Dockerfile .
+docker build -t dynamo:latest-vllm-dev -f container/rendered.Dockerfile .
 
 # Build a local-dev image. The local-dev image will run as `dynamo` with UID/GID matched to your host user,
 # which is useful when mounting partitions for development.