[PATCH] mailmap: Update comments for with format and more detalis

[Kees Cook <keescook@chromium.org>]

Without having first read the git-shortlog man-page first, the format
of .mailmap may not be immediately obvious. Add comments with pointers
to the man-page, along with other details.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
I'm adding this to my earlier .mailmap update series:
https://lore.kernel.org/lkml/20200730183702.702552-1-keescook@chromium.org/
---
 .mailmap | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/.mailmap b/.mailmap
index 6c1c04a63b18..3a991e19928c 100644
--- a/.mailmap
+++ b/.mailmap
@@ -2,11 +2,16 @@
 # This list is used by git-shortlog to fix a few botched name translations
 # in the git archive, either because the author's full name was messed up
 # and/or not always written the same way, making contributions from the
-# same person appearing not to be so or badly displayed.
+# same person appearing not to be so or badly displayed. Also allows for
+# old email addresses to map to new email addresses.
 #
+# For format details, see "MAPPING AUTHORS" in "man git-shortlog".
+#
+# Please keep this list dictionary sorted.
+#
+# This comment is parsed by git-shortlog:
 # repo-abbrev: /pub/scm/linux/kernel/git/
 #
-
 Aaron Durbin <adurbin@google.com>
 Adam Oldham <oldhamca@gmail.com>
 Adam Radford <aradford@gmail.com>
-- 
2.25.1


-- 
Kees Cook