Add some doc to let developers know about the `-s` flag
with `git commit`.
We were seeing some people writing the sign-off manually.
Signed-off-by: Stephen Worley <sworley@cumulusnetworks.com>
using the signed-off-by process as the Linux kernel. In short, you must include
a ``Signed-off-by`` tag in every patch.
+An easy way to do this is to use ``git commit -s`` where ``-s`` will automatically
+append a signed-off line to the end of your commit message. Also, if you commit
+and forgot to add the line you can use ``git commit --amend -s`` to add the
+signed-off line to the last commit.
+
``Signed-off-by`` is a developer's certification that they have the right to
submit the patch for inclusion into the project. It is an agreement to the
:ref:`Developer's Certificate of Origin <developers-certificate-of-origin>`.