[upstream] Register contact information during account setup

It is important to register contact information in Gerrit.
Otherwise developers cannot push changes for review.

From my experience of upstream trainings in Japan, this is
one of traps which developers hit when failing to push a change.

Change-Id: Idc68d56b3e603d29b30ec1dc8de0e7f9dfe46d78
Closes-Bug: #1616942

doc/upstream-training/accounts.rst

@@ -130,3 +130,43 @@ Contributors From the U.S. Government
    Agreement <https://wiki.openstack.org/wiki/GovernmentCLA>`_. Contact the
    `OpenStack Foundation <mailto:communitymngr@openstack.org>`_ to initiate
    this process.
+
+Contact Information
+===================
+
+What is it?
+-----------
+
+You need to register your contact information including your full name, email
+address and offline contact information.
+
+Your full name and email address will be public and the email address needs to
+match the email address which you plan to use in your commits.
+
+The other contact information including postal address and phone numbers will
+be kept confidential and is only used as a fallback record in the unlikely
+event the OpenStack Foundation needs to reach you directly over code
+contribution related matters.
+
+This contact information can be easily updated later if desired, but make sure
+the primary email address always matches the one you set for your OpenStack
+Foundation Membership. Otherwise, Gerrit will give you an error message and
+refuse to accept your contact information.
+
+Register Contact Information
+----------------------------
+
+#. Visit `Contact Information
+   <https://review.openstack.org/#/settings/contact>`__
+   in Gerrit's settings.
+#. Fill your contact information and click 'Save Changes'.
+#. Once your contact information is saved successfully,
+   you will see the line **"Contact information last updated ...."**
+   just above the forms of mailing address.
+
+.. image:: ./source/_assets/tools/account-setup/4.png
+
+.. note::
+
+   If you do not register your contact information,
+   you cannot upload your any changes to Gerrit.