Provide more detail for use of `validate-traffic`

Can you please provide more examples of using `validate-traffic`. I have tried passing a directory as the `` and `oav` spots if _that directory does not exist_ but I don't see it make any attempt to actually look at files in the directory. I'm probably doing something wrong but I'd rather not start code reading to find out what ;-).

Locate the documentation and CLI entry point for validate-traffic, then read how and oav are described. Add concrete directory examples, including the nonexistent-directory case, and verify that the examples match the command's observed behavior.

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