Az DevOps Security Page needs examples

Trying to test some of these commands and the syntax is unclear and the errors are not useful.

Tried to list permissions for a user account. `az devops security permission list --subject user` and got an error.

ArgumentParseError: the following arguments are required: --namespace-id/--id
Try this: 'az account list'
Still stuck? Run 'az devops security permission list --help' to view all commands or go to 'https://docs.microsoft.com/en-us/cli/azure/reference-index?view=azure-cli-latest' to learn more

None of this is particular useful. An example call that has the correct syntax for this, and the others, would be very helpful.

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#### Document Details

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* ID: a283a450-7f6b-ceef-6fbd-f4e1d5129383
* Version Independent ID: 7361dfa6-28ed-1074-783e-baa233c3a308
* Content: [az devops security permission](https://docs.microsoft.com/en-us/cli/azure/ext/azure-devops/devops/security/permission?view=azure-cli-latest#ext_azure_devops_az_devops_security_permission_list)
* Content Source: [latest/docs-ref-autogen/ext/azure-devops/devops/security/permission.yml](https://github.com/MicrosoftDocs/azure-docs-cli/blob/master/latest/docs-ref-autogen/ext/azure-devops/devops/security/permission.yml)
* GitHub Login: @rloutlaw
* Microsoft Alias: **routlaw**