[docker] Support multiple node types (#10504)

doc/source/cluster/autoscaling.rst

@@ -114,3 +114,15 @@ The ``worker_setup_commands`` field (and also the ``initialization_commands`` fi
 
     worker_setup_commands:
         - pip install tensorflow-gpu  # Example command.
+
+Docker Support
+~~~~~~~~~~~~~~
+The ``worker_image`` and ``pull_before_run`` fields override the correpsonding field in the top level ``docker`` section for the node type. The ``worker_run_options`` field is combined with top level ``docker: run_options`` field to produce the docker run command for the given node_type. The following configuration is for a GPU enabled node type.
+
+.. code::
+
+    pull_before_run: True
+    worker_image:
+        - rayproject/ray-ml:latest-gpu
+    worker_run_options:
+        - --runtime=nvidia