Add some instructions

Author: adamtheturtle

CONTRIBUTING.rst

@@ -205,6 +205,38 @@ Prerequisites
 Perform a Release
 ~~~~~~~~~~~~~~~~~
 
+#. Install keyring
+
+   Make sure that `keyring <https://pypi.org/project/keyring/>`__ is available on your path.
+
+   E.g.:
+
+   .. code:: sh
+
+      curl https://raw.githubusercontent.com/mitsuhiko/pipsi/master/get-pipsi.py | python
+      pipsi install keyring
+
+#. Set up PyPI credentials
+
+Register at `PyPI <https://pypi.org>`__.
+
+Add the following information to ``~/.pypirc``.
+
+.. code:: ini
+
+   [distutils]
+    index-servers=
+        pypi
+
+    [pypi]
+    username = <Your PyPI username>
+
+Store your PyPI password:
+
+.. code:: sh
+
+   keyring set https://upload.pypi.org/legacy/ <Your PyPI username>
+
 #. Get a GitHub access token:
 
    Follow the `GitHub instructions <https://help.github.com/articles/creating-a-personal-access-token-for-the-command-line/>`__ for getting an access token.