For a while now, Jeffery has helped quite a lot with Python, and is now
unofficial go-to guy [for problems] with Python packages.

This change adds him as co-maintainer [if he also agrees].

I'm not going away; I'll be still doing the same work for Python.
This change serves to recognize Jeffery in an official way, since he's
already taking on these things. And 2 co-maintainers is better in case one
kicks the bucket [by accident].

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>