NGINXaaS for Azure Configuration upload doc improvement

[JTorreG]

Overview

https://docs.nginx.com/nginxaas/azure/getting-started/nginx-configuration/nginx-configuration-azure-cli/#create-a-configuration

Needs improvement

Description

We have two ways for our customers to upload a config:

Plain files.
Tarball uploads
We should look at splitting up the two ways in our docs to make it more visible as both use-cases are valid and can be used by our customers.