doc: config: replace backtick with apostrophe for possessive
Revert back to “Git's” which was used before d30c5cc4592 (doc: convert
git-mergetool options to new synopsis style, 2025-05-25) accidentally
changed it.
Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
authored by