Undocumented deployment operationStatuses API

Hello,
I have found an existing API that is undocumented and so would like to get help having it added.

To replicate / identify the API call(s), I performed the following az cli command:
az vm create -n MyVm -g MyResourceGroup --image UbuntuLTS --location eastus --generate-ssh-keys

A deployment is created/updated with this call:
https://github.com/Azure/azure-rest-api-specs/blob/master/specification/resources/resource-manager/Microsoft.Resources/stable/2020-10-01/resources.json#L1619

And in the response for that call is a header that looks like:
Azure-AsyncOperation=https://management.azure.com/subscriptions/{subscriptionId}/resourcegroups/{resourceGroupName}/providers/Microsoft.Resources/deployments/{deploymentName}/operationStatuses/{operationId}?api-version=2020-06-01

This makes the cli hit this endpoint, but this endpoint is not documented. I'm not sure which API versions it is available in, other than 2020-06-01.

Hopefully this is enough info so that someone can help me add this operationStatuses endpoint to the documentation.

Start with specification/resources/resource-manager/Microsoft.Resources/stable/2020-10-01/resources.json around line 1619 and trace the Azure-AsyncOperation header to the operationStatuses endpoint using api-version=2020-06-01. Document the endpoint and identify the API versions in which it is available, using the existing resource specification structure as a guide.

Written by the indexing model from the issue text.