Migrate autoscaling azure interface actions into main

Author: Sieboldianus

docs/source/kubernetes/microsoft/step-zero-azure.md

@@ -310,6 +310,47 @@ If you create the cluster using the Azure Portal you must enable RBAC.
 RBAC is enabled by default when using the command line tools.
 ```
 
+11. Enabling Autoscaling (Optional)
+
+    If your cluster is prepared for autoscaling (`--enable-cluster-autoscaler`),
+    move to the Azure Portal to enable autoscaling and set rules to manage the Cluster Autoscaler.
+
+    Navigate to your active subscription on the [Portal](https://portal.azure.com/).
+
+    Under "Resources", select the VMSS.
+    It should be named something like `aks-nodepool1-<random-str>-vmss`.
+
+    ```{image} ../../_static/images/azure/select_vmss.png
+    :align: center
+    ```
+
+    From the left-hand menu, select "Scaling".
+    Click the blue "Custom autoscale" button and an autogenerated form for a scale condition will appear.
+    We will add two new rules to this condition:
+
+    - Increase the instance count by 1 when the average CPU usage over 10 minutes is greater than 70%
+    - Decrease the instance count by 1 when the average CPU usage over 10 minutes is less than 5%
+
+    ```{image} ../../_static/images/azure/scale_condition.png
+    :align: center
+    ```
+
+    Make sure the "Scale based on metric" option is selected and click "+ Add new rule", another autogenerated form will appear.
+    This will be pre-filled with the required settings to fulfill our first rule, so save it by clicking "Update" and click "+ Add new rule" again.
+
+    ```{image} ../../_static/images/azure/scale_out.png
+    :align: center
+    ```
+
+    The second form needs to be edited for the second rule to decrease the instance count by 1 when the average CPU usage over 10 minutes is less than 5%.
+    Save this rule and then save the overall scale condition, the cluster will be updated automatically.
+
+    ```{image} ../../_static/images/azure/scale_in.png
+    :align: center
+    ```
+
+    This form can also be used to change `--node-count`/`--min-count`/`--max-count` that was set previously by using the "Instance limits" section of the scale condition ("Default", "Minimum" and "Maximum" respectively).
+
 Congrats. Now that you have your Kubernetes cluster running, it's time to
 begin {ref}`setup-helm`.