doc txt & -h consistency: make "commit" consistent

Make the "-h" output of "git commit" consistent with the *.txt version
by exhaustively listing the options that it takes.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/commit.c

@@ -40,7 +40,14 @@
 #include "pretty.h"
 
 static const char * const builtin_commit_usage[] = {
-	N_("git commit [<options>] [--] <pathspec>..."),
+	N_("git commit [-a | --interactive | --patch] [-s] [-v] [-u<mode>] [--amend]\n"
+	   "           [--dry-run] [(-c | -C | --squash) <commit> | --fixup [(amend|reword):]<commit>)]\n"
+	   "           [-F <file> | -m <msg>] [--reset-author] [--allow-empty]\n"
+	   "           [--allow-empty-message] [--no-verify] [-e] [--author=<author>]\n"
+	   "           [--date=<date>] [--cleanup=<mode>] [--[no-]status]\n"
+	   "           [-i | -o] [--pathspec-from-file=<file> [--pathspec-file-nul]]\n"
+	   "           [(--trailer <token>[(=|:)<value>])...] [-S[<keyid>]]\n"
+	   "           [--] [<pathspec>...]"),
 	NULL
 };