[Readme config] Alias for discriminator options not working

[fengzhou-msft]

--factory-git-hub-configuration and --factory-vsts-configuration are discriminator options for therepoConfiguration property in the swagger to create a data factory.
The violate the option_length_too_long linter rule. I tried to add alias for them, but the below configuration does not work.

    - where:
          group: Factories
          type: FactoryGitHubConfiguration
      alias:
          - factory-git-hub-configuration
          - github-config
    - where:
          group: Factories
          type: FactoryVSTSConfiguration
      alias:
          - factory-vsts-configuration
          - vsts-config

My current workaround is to manually add the alias. I need to modify _help.y and _params.py in manual folder.