fflash: Add more links in README

BUG=None
TEST=None

Change-Id: I30e78578b1c827c9fcdc44dd5b3edbe3fb744803
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/3983806
Commit-Queue: Li-Yu Yu <aaronyu@google.com>
Reviewed-by: Terry Cheong <htcheong@chromium.org>
Tested-by: Li-Yu Yu <aaronyu@google.com>
1 file changed