Update README

README.md

@@ -44,6 +44,7 @@ Workflows.
       - [Manual Approval Step](#manual-approval-step)
     - [Pipeline YAML Comments](#pipeline-yaml-comments)
     - [Common Configuration for Docker Asset Publishing Steps](#common-configuration-for-docker-asset-publishing)
+  - [AWS China partition support](#aws-china-partition-support)
   - [Tutorial](#tutorial)
   - [Not supported yet](#not-supported-yet)
   - [Contributing](#contributing)
@@ -644,6 +645,19 @@ const pipeline = new GitHubWorkflow(app, 'Pipeline', {
 app.synth();
 ```
 
+## AWS China partition support
+
+The `CDK_AWS_PARTITION` environment variable can be used to specify the AWS partition for the pipeline.
+If it's specified to `aws-cn`, the assets generated by pipeline will reference the resources in
+`.amazonaws.com.cn` instead of `.amazonaws.com.cn`.
+
+If `CDK_AWS_PARTITION` environment variable is not specified, the default behaviour for the pipeline is
+to use the `aws` partition.
+
+It is not possible to have a pipeline that deploys to both `aws` and `aws-cn` partitions.
+If you need to deploy to both partitions, you will need to create two separate pipelines.
+The stages and stacks can be shared between the two pipelines.
+
 ## Tutorial
 
 You can find an example usage in [test/example-app.ts](./test/example-app.ts)