title: Discord.py: How to get member join date?
body: <p>I'm trying to make a command like this:
  <code>r!info user</code> which will give all information about the user who is tagged there. But I'm not sure how to get the date at which the member joined the server.
  I'm using Discord.py with Python 3.9.
  Any help will be appreciated.
  Thank you</p>