doc: am: add missing config am.messageId

Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/config/am.adoc b/Documentation/config/am.adoc
index 19ef5aa00c46824088405f6f0fc500c18c56bb4e..e9561e12d7467e2058c1334122aa7c33e3e8a170 100644 (file)
--- a/Documentation/config/am.adoc
+++ b/Documentation/config/am.adoc
@@ -12,3 +12,9 @@ am.threeWay::
        records the identity of blobs it is supposed to apply to and we
        have those blobs available locally (equivalent to giving the
        `--3way` option from the command line). Defaults to `false`.
+
+am.messageId::
+       Add a `Message-ID` trailer based on the email header to the
+       commit when using linkgit:git-am[1] (see
+       linkgit:git-interpret-trailers[1]). See also the `--message-id`
+       and `--no-message-id` options.