enhance readme on commands example

configs/metadata.json

@@ -1,7 +1,8 @@
 {
     "schema": "https://github.com/Project-MONAI/MONAI-extra-test-data/releases/download/0.8.1/meta_schema_20220324.json",
-    "version": "0.2.0",
+    "version": "0.2.1",
     "changelog": {
+        "0.2.1": "enhance readme on commands example",
         "0.2.0": "update license files",
         "0.1.0": "complete the first version model package",
         "0.0.1": "initialize the model package structure"

docs/readme.md

@@ -58,6 +58,7 @@ python -m monai.bundle run training \
 ```
 
 Override the `train` config to execute multi-GPU training:
+
 ```
 torchrun --standalone --nnodes=1 --nproc_per_node=2 -m monai.bundle run training \
     --meta_file configs/metadata.json \
@@ -65,6 +66,9 @@ torchrun --standalone --nnodes=1 --nproc_per_node=2 -m monai.bundle run training
     --logging_file configs/logging.conf
 ```
 
+Please note that the distributed training related options depend on the actual running environment, thus you may need to remove `--standalone`, modify `--nnodes` or do some other necessary changes according to the machine you used.
+Please refer to [pytorch's official tutorial](https://pytorch.org/tutorials/intermediate/ddp_tutorial.html) for more details.
+
 Override the `train` config to execute evaluation with the trained model:
 
 ```