bpo-42560: simplify/merge architecture info in Tkinter docs (GH-27839)

Co-authored-by: Łukasz Langa <lukasz@langa.pl>
Co-authored-by: E-Paine <63801254+E-Paine@users.noreply.github.com>
(cherry picked from commit e41912c6348362489d2514565a70782591f23902)

Co-authored-by: Mark Roseman <mark@markroseman.com>