Add slide #12 of upstream training

Change-Id: Iea83c6ac0a9eb13bf16d8e63b4fcf5454403a832

doc/upstream-training/12-howtocontribute.rst

@@ -0,0 +1,64 @@
+http://launchpad.net/
+=====================
+
+.. image:: ./_assets/12-01-launchpad-net.png
+  :width: 75%
+
+----
+
+http://review.openstack.org
+===========================
+
+.. image:: ./_assets/12-02-review.png
+  :width: 100%
+
+----
+
+Sign In
+=======
+
+.. image:: ./_assets/12-03-signin.png
+
+----
+
+No agreement
+============
+
+.. image:: ./_assets/12-04-no-agreement.png
+
+----
+
+New agreement
+=============
+
+.. image:: ./_assets/12-05-new-agreement.png
+
+----
+
+Sign the Individual agreement
+=============================
+
+.. image:: ./_assets/12-06-individual-agreement.png
+
+----
+
+Do you work at a company?
+=========================
+
+- If your contribution is on behalf of a company, have your managers sign the Corporate Contributor License Agreement
+- https://wiki.openstack.org/wiki/How_To_Contribute#Contributors_License_Agreement
+
+----
+
+Signed agreement
+================
+
+.. image:: ./_assets/12-07-signed-agreement.png
+
+----
+
+Exercise
+========
+
+Apply for individual membership and sign the CLA
+