Add documentation on the multi-arch flag

Signed-off-by: Bryan Cox <brcox@redhat.com>

docs/content/how-to/aws/create-heterogeneous-nodepools.md

@@ -0,0 +1,38 @@
+---
+title: Create Heterogeneous NodePools on AWS HostedClusters
+---
+
+# Create Heterogeneous NodePools on AWS HostedClusters
+## Create Heterogeneous NodePools Through the HyperShift CLI
+The `multi-arch` flag was added to the HyperShift CLI in OCP 4.16. The `multi-arch` flag indicates an expectation that the Hosted Cluster will support both amd64 and arm64 NodePools.
+
+When this flag is set, it will ensure:
+
+* if a release image is supplied, the release image must be a multi-arch release image
+* if a release stream is supplied, the release stream must be a multi-arch stream
+
+
+!!! note 
+
+    An individual NodePool only supports one CPU architecture and cannot support multiple CPU archiectures within the same NodePool.
+
+
+```shell linenums="1"
+REGION=us-east-1
+CLUSTER_NAME=example
+BASE_DOMAIN=example.com
+AWS_CREDS="$HOME/.aws/credentials"
+PULL_SECRET="$HOME/pull-secret"
+RELEASE_IMAGE=quay.io/openshift-release-dev/ocp-release:4.16.0-ec.3-multi
+
+hypershift create cluster aws \
+  --name $CLUSTER_NAME \
+  --node-pool-replicas=3 \
+  --base-domain $BASE_DOMAIN \
+  --pull-secret $PULL_SECRET \
+  --aws-creds $AWS_CREDS \
+  --region $REGION \
+  --release-image $RELEASE_IMAGE \
+  --generate-ssh \
+  --multi-arch
+```

docs/mkdocs.yml

@@ -66,6 +66,7 @@ nav:
     - how-to/automated-machine-management/performance-profiling.md
   - 'AWS':
     - how-to/aws/create-aws-hosted-cluster-arm-workers.md
+    - how-to/aws/create-heterogeneous-nodepools.md
     - how-to/aws/create-infra-iam-separately.md
     - how-to/aws/create-aws-hosted-cluster-multiple-zones.md
     - how-to/aws/deploy-aws-private-clusters.md