Fixed #16779 - Added a contributing tutorial

Thank-you Taavi Taijala for the draft patch!

docs/index.txt

@@ -47,7 +47,8 @@ Are you new to Django or to programming? This is the place to start!
   :doc:`Part 4 <intro/tutorial04>`
 
 * **Advanced Tutorials:**
-  :doc:`How to write reusable apps <intro/reusable-apps>`
+  :doc:`How to write reusable apps <intro/reusable-apps>` |
+  :doc:`Writing your first patch for Django <intro/contributing>`
 
 The model layer
 ===============

docs/internals/contributing/writing-code/unit-tests.txt

@@ -38,6 +38,8 @@ with this sample ``settings`` module, ``cd`` into the Django
 If you get an ``ImportError: No module named django.contrib`` error,
 you need to add your install of Django to your ``PYTHONPATH``.
 
+.. _running-unit-tests-settings:
+
 Using another ``settings`` module
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -133,6 +135,8 @@ Then, run the tests normally, for example:
 
     ./runtests.py --settings=test_sqlite admin_inlines
 
+.. _running-unit-tests-dependencies:
+
 Running all the tests
 ~~~~~~~~~~~~~~~~~~~~~
 

docs/intro/index.txt

@@ -15,6 +15,7 @@ place: read this material to quickly get up and running.
    tutorial04
    reusable-apps
    whatsnext
+   contributing
 
 .. seealso::