[Reference feedback]: the source needs to be updated to fix the Warning note rendered in the reference document

### Type of issue

Other (describe below)

### Reference command name

az mysql flexible-server update

### Feedback

The ["Warning" note](https://review.learn.microsoft.com/en-us/cli/azure/mysql/flexible-server?branch=main&branchFallbackFrom=pr-en-us-5270&view=azure-cli-latest#az-mysql-flexible-server-update) in the reference document for "[_help.py](https://github.com/Azure/azure-cli/blob/67013bf113c4ece2cb34611737a29f8c4a8ba5a4/src/azure-cli/azure/cli/command_modules/mysql/_help.py#L327-L328)" is not rendered properly.

This is due to the ">" after "long-summary:" in YAML indicates a folded style, which collapses newlines into spaces. Recommended fix: use "|" or refer to yaml standards to update in "_help.py".

### Page URL

https://review.learn.microsoft.com/en-us/cli/azure/mysql/flexible-server?branch=main&branchFallbackFrom=pr-en-us-5270&view=azure-cli-latest#az-mysql-flexible-server-update

### Content source URL

https://github.com/Azure/azure-cli/blob/67013bf113c4ece2cb34611737a29f8c4a8ba5a4/src/azure-cli/azure/cli/command_modules/mysql/_help.py#L326-L328

### Author

_No response_

### Document Id

_No response_