Add section on obtaining a python.org email address for core team members (#1495)

Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>

Author: 3 people

core-developers/become-core-developer.rst

@@ -60,6 +60,14 @@ are granted through these steps:
      were in the form of a separate post on the already open topic with
      the poll.
 
+Getting a python.org email address
+----------------------------------
+
+Members of the core team can get an email address on the python.org domain.
+For more details refer to the `python.org email policy
+<https://www.python.org/psf/records/board/policies/email/>`_.
+
+
 Poll template
 =============