[Feature Request] use slackdump's playwright auth strategy

[Jack Ellenberger]

As @mootari suggests i / we should think about using a solution like @rusq's https://github.com/rusq/slackdump/blob/master/doc/login-auto.rst to capture tokens and cookies rather than requiring a chrome extension or browser fiddling. I hate headless browsers but it seems like a way better UX.

• Either document how to pipe one project to another, or integrate the slackdump project directly