az init | Add long-summary with detail informatoin

[dbradish-microsoft]

See email thread with subject "az init and az self-test".

Please add more information to the az init autogenerated content

1. Why would someone use this over az config?
2. How is az init the same/different from az config
3. What all can a customer init?
4. How does one "uninit" something?
5. What is the expected console output when it completes?
6. What is included in a "configuration bundle"?

We need to give information like "az init starts an interactive experience ..." etc.

Reference link

https://learn.microsoft.com/en-us/cli/azure/reference-index#az-init

[yonzhan]

az init