id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,active_lock_reason,draft,pull_request,body,reactions,performed_via_github_app,state_reason,repo,type
707752322,MDU6SXNzdWU3MDc3NTIzMjI=,4455,Document units for polyfit when dimension is time,22488770,open,0,,,2,2020-09-23T23:51:02Z,2021-06-23T11:12:55Z,,CONTRIBUTOR,,,,"<!-- Please do a quick search of existing issues to make sure that this has not been asked before. -->

**Is your feature request related to a problem? Please describe.**
I think (please correct me if I'm wrong) when using polyfit with dim='time' the units of the output slope are [data_units]/ns, but this not explained in the docstring or in the documentation on the webpage. I figured this out eventually but it could be confusing for new users.

**Describe the solution you'd like**
Mention in the documentation and/or docstring that the units for time will be ns

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