branch: advice using git-help(1) instead of man(1)
8fbd903e (branch: advise about ref syntax rules, 2024-03-05) added an advice about checking git-check-ref-format(1) for the ref syntax rules. The advice uses man(1). But git(1) is a multi-platform tool and man(1) may not be available on some platforms. It might also be slightly jarring to see a suggestion for running a command which is not from the Git suite. Let’s instead use git-help(1) in order to stay inside the land of git(1). This also means that `help.format` (for `man`, `html` or other formats) will be used if set. Also change to using single quotes (') to quote the command since that is more conventional. While here let’s also update the test to use `{SQ}`, which is more readable and easier to edit. Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name> Signed-off-by: Junio C Hamano <gitster@pobox.com>