Preview template of an existing `html` file

[Marvin9]

Checklist

• [X] I agree to the terms within the Auth0 Code of Conduct.

Describe the problem you'd like to have solved

https://auth0.github.io/auth0-cli/auth0_branding_templates.html

We get a preview from the temporary file with the command mentioned in link above. However it would've been much better if I was able to get a preview for existing HTML file.

Describe the ideal solution

It should operate as same way as auth0 branding templates update command, except that it should accept the html file and doesn't ask to "save the template" before it is exited.

Maybe something like

auth0 branding templates preview /path/to/foo.html

Alternatives and current workarounds

No response

Additional context

No response