[3.11] gh-95271: Extract placeholders howto from sqlite3 tutorial (GH-95522) (#95677)

Co-authored-by: CAM Gerlach <CAM.Gerlach@Gerlach.CAM>
Co-authored-by: Ezio Melotti <ezio.melotti@gmail.com>
(cherry picked from commit b24e8b28a7dc585ba367a959be83393f2352d21d)

Co-authored-by: Erlend Egeberg Aasland <erlend.aasland@protonmail.com>