How to specify the template.yml when running fun deploy

I have several regions that I prepare to deploy, in which case I decide to apply the different template.yml whose configuration was defined to be suitable for specific regions. although I have looked for the manual, I haven't found any arguments which I can use to specify the template.yml file.

there is my anticipation:

```shell
fun deploy --config=template-xxx.yml
```

Start with the fun deploy command and its help or manual to verify how deployment configuration is currently selected. Check whether template.yml selection is covered by existing command tests, then confirm that specifying template-xxx.yml works for choosing a region-specific configuration.

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