[3.11] gh-85747: Active voice & suggested edits, 'running/stopping loop' & 'callbacks' subsections of asyncio-eventloop.rst (GH-100270) (#102006)

Note: the `timeout` parameter was not added until 3.12.

(cherry picked from commit c4de6b1d52304a0a9cdfafc1dad5098993710404)

Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM>
Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>.
Co-authored-by: Brian Skinn <brian.skinn@gmail.com>