Customer feedback | az containerapp hostname bind | Optional parameters, that are actually conditional, are not explained

### Describe the bug

This GitHub issue is being created from azDO UUF [#301974](https://dev.azure.com/msft-skilling/Content/_workitems/edit/301974).
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### Engineering request
1. Clarify if this example "looks for OR creates" or "looks for AND creates if not found"
2. Both the `--certificate` and `--environment` parameters are listed as optional, yet according to the customer error, one is required if the other is not supplied. Please expand the `short-summary` description of both parameters and include a "required if..." statement. Example: `Name or resource id of the certificate. REQUIRED if the "environment" parameter is not used`.

### Related command
az containerapp hostname

### Customer feedback

Title:
az containerapp hostname | Microsoft Learn

Verbatim:
No, the documentation is not correct for az containerapp hostname bind, it does not create a managed certificate but gives error: Please specify at least one of parameters: --certificate and --environment

Verbatim Id:
8c355eb4-8962-ef11-bfe3-0022480bc06c

Live URL:
https://learn.microsoft.com/en-us/cli/azure/containerapp/hostname

GitHub URL:
https://github.com/MicrosoftDocs/azure-docs-cli/blob/live/2020-09-01-hybrid/docs-ref-autogen/containerapp/hostname.yml

### Related command

az containerapp hostname bind

### Errors

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### Issue script & Debug output

.

### Expected behavior

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### Environment Summary

Azuer CLI 2.65.0

### Additional context

_No response_