Add next steps, context resources to developer docs

Ref: #2794.

docs/development/getting-started.rst

@@ -406,6 +406,37 @@ Building the docs requires Python 3.6. If it is not installed, the
   Makefile:53: recipe for target '.state/env/pyvenv.cfg' failed
   make: *** [.state/env/pyvenv.cfg] Error 127
 
+What next?
+----------
+
+Please look at our `open issues that are labelled "good first
+issue"`_, find one you want to work on, comment on it to say you're
+working on it, then submit a pull request. Use our
+:doc:`submitting-patches` documentation to help.
+
+Talk with us
+^^^^^^^^^^^^
+
+You can find us via a `GitHub`_ issue, ``#pypa`` or ``#pypa-dev`` `on
+Freenode`_, or the `pypa-dev mailing list`_, to ask questions or get
+involved. And you can meet us in person at `packaging sprints`_.
+
+Learn about Warehouse and packaging
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Resources to help you learn Warehouse's context:
+
+-  `the Warehouse
+   roadmap <https://wiki.python.org/psf/WarehouseRoadmap>`__
+-  `blog posts, mailing list messages, and notes from our core developer
+   meetings <https://wiki.python.org/psf/PackagingWG>`__
+- :doc:`../application`
+-  `the PyPA's list of presentations and
+   articles <https://www.pypa.io/en/latest/presentations/>`__
+-  `PyPA's history of Python
+   packaging <https://www.pypa.io/en/latest/history/>`__
+
+
 .. _`pip`: https://pypi.org/project/pip
 .. _`sphinx`: https://pypi.org/project/Sphinx
 .. _`reStructured Text`: http://sphinx-doc.org/rest.html
@@ -414,3 +445,4 @@ Building the docs requires Python 3.6. If it is not installed, the
 .. _`on Freenode`: https://webchat.freenode.net/?channels=%23pypa-dev,pypa
 .. _`pypa-dev mailing list`: https://groups.google.com/forum/#!forum/pypa-dev
 .. _`Test PyPI`: https://test.pypi.org/
+.. _`packaging sprints`: https://wiki.python.org/psf/PackagingSprints