az init | Add long-summary with detail informatoin

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