Removed gitter from contributing.rst (#49204)

Replaced gitter and user mailing list with text about the contributor community

Author: noatamir

doc/source/development/contributing.rst

@@ -45,8 +45,13 @@ assigned issues, since people may not be working in them anymore. If you want to
 that is assigned, feel free to kindly ask the current assignee if you can take it
 (please allow at least a week of inactivity before considering work in the issue discontinued).
 
-Feel free to ask questions on the `mailing list
-<https://groups.google.com/forum/?fromgroups#!forum/pydata>`_ or on `Gitter`_.
+We have several :ref:`contributor community <community>` communication channels, which you are
+welcome to join, and ask questions as you figure things out. Among them are regular meetings for
+new contributors, dev meetings, a dev mailing list, and a slack for the contributor community.
+All pandas contributors are welcome to these spaces, where they can connect with each other. Even
+maintainers who have been with us for a long time felt just like you when they started out, and
+are happy to welcome you and support you as you get to know how we work, and where things are.
+Take a look at the next sections to learn more.
 
 .. _contributing.bug_reports:
 
@@ -346,8 +351,6 @@ The branch will still exist on GitHub, so to delete it there do::
 
     git push origin --delete shiny-new-feature
 
-.. _Gitter: https://gitter.im/pydata/pandas
-
 
 Tips for a successful pull request
 ==================================