add back in ARM docs

Author: Denise Schannon

content/rancher/v2.x/en/installation/arm64-platform/_index.md

@@ -0,0 +1,27 @@
+---
+title: Running on ARM64 (Experimental)
+weight: 7600
+---
+
+_Available as of v2.2.0_
+
+> **Important:**
+>
+> Running on an ARM64 platform is currently an experimental feature and is not yet officially supported in Rancher. Therefore, we do not recommend using ARM64 based nodes in a production environment.
+
+The following options are available when using an ARM64 platform:
+
+- Running Rancher on ARM64 based node(s)
+  - Only [Single Node Install]({{< baseurl >}}/rancher/v2.x/en/installation/single-node/)
+- Create custom cluster and adding ARM64 based node(s)
+  - Kubernetes cluster version must be 1.12 or higher
+  - CNI Network Provider must be [Flannel]({{< baseurl >}}/rancher/v2.x/en/faq/networking/cni-providers/#flannel)
+- Importing clusters that contain ARM64 based nodes
+  - Kubernetes cluster version must be 1.12 or higher
+
+Please see [Cluster Options]({{< baseurl >}}/rancher/v2.x/en/cluster-provisioning/rke-clusters/options/) how to configure the cluster options.
+
+The following features are not tested:
+
+* Monitoring, alerts, notifiers, pipelines and logging
+* Launching apps from the catalog