[3.10] bpo-41963: document that ConfigParser strips off comments (GH-26197) (GH-26214)

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Laura Gutierrez Funderburk <58710704+lgfunderburk@users.noreply.github.com>
Co-authored-by: Jürgen Gmach <juergen.gmach@googlemail.com>

(cherry picked from commit 02ee8191263848f8c8999f72286148946b83e5c9)
3 files changed