git: Set interactive.singleKey

In interactive commands, allow the user to provide one-letter input with
a single key (i.e., without hitting enter). Currently this is used by
the --patch mode of git-add(1), git-checkout(1), git-restore(1),
git-commit(1), git-reset(1), and git-stash(1). Note that this setting is
silently ignored if portable keystroke input is not available; requires
the Perl module Term::ReadKey.[1]

[1] - git-config(1)

.config/git/config

@@ -50,6 +50,7 @@
 	defaultBranch = main
 [interactive]
 	diffFilter = diff-so-fancy --patch
+	singleKey = true
 [log]
 	follow = true
 [merge]